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Abstract

¹H and ¹³C nuclear magnetic resonance (NMR) data and specific rotations of eremophilane sesquiterpenoids are cumulated as a series of review articles. This fourth chapter focuses on furanoeremophilanes bearing 10H with C-3 oxygen functionality, and 175 10H-furanoeremophilanes with 3-O functionality are listed in 38 tables. Those with 15,6-lactones and 6,15-ethers are included in this chapter. Dihydrofurans, lactols, dimers, nor- and seco-compounds, and other related compounds, are not included in this chapter. These data may help chemists working in the area of natural products chemistry and synthetic scientists as well as computational chemists.

Keywords

sesquiterpenoids eremophilanes NMR specific rotation terpenoids

Introduction

Isolation of numerous eremophilane-type sesquiterpenoids has been reported, and the number of compounds continues to increase. As a part of an ongoing series of reviews,^1-3 data of 175 furanoeremophilane sesquiterpenoids are listed in Tables 1–38. This chapter focuses on furanoeremophilanes bearing 10H with C-3 oxygen functionality. The eremophilane skeleton, esters attached to compounds, and their numberings are shown in Figure 1.¹ The compounds mentioned in this chapter are shown in Figures 2–14. Dihydrofurans, lactols, dimers, nor- and seco-compounds, and other related compounds will be discussed in separate chapters in the future. In the case of compounds having more than 2 acyloxy groups, the one substituted in the lower numbered position is numbered with a prime, the next with a double prime, and so on. The coupling constants are sorted from the largest to the smallest; the order of the type of splitting pattern, d, t, or q, must correspond to the value of the coupling constant. In the case of apparent situation, original data were fixed to the proper order, or the problem with the data pointed out in the footnotes. The data that were not assigned in the original papers were tentatively included in the tables without any supporting evidence. The solvents used for nuclear magnetic resonance (NMR) and [α]_D were indicated with abbreviations (A: acetone or acetone-d₆; B: benzene or benzene-d₆; C: chloroform or chloroform-d; D: dimethyl sulfoxide or dimethyl sulfoxide-d₆; E: ethanol; F: dichloromethane; H: hexane; M: methanol or methanol-d_4; P: pyridine or pyridine-d₅; and T: carbon tetrachloride). Solvents were selected by original chemists depending on the solubility and the stability of compounds, or the easiness of analyses. Source of compounds were also abbreviated (Ca: Cacalia [current Parasenecio, however original description has been remained]; Cr: Cremanthodium; E: Eremophila; F: Farfugium; L: Ligularia; P: Petasites; S: Senecio; V: Valeriana). These data may help chemists working in the area of natural products chemistry and synthetic scientists as well as computational chemists.^4,5

Figure 1.

The eremophilane skeleton, esters, and their numberings.

Figure 2.

Compounds 1-12.

Table 1.

Data of Compounds 1-4.

Compound	1	2 ^a	2	3	3	4	4
(solvent)	nd^b	¹H (T)	¹H (T)	¹H (T)	¹H (T)	¹H (T)	¹H (C)
1	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd
2	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd
3	3.71 (m)	3.84 (m)	3.78 (m)	4.12 (m)	4.08 (m)	–	–
4	nd	nd	nd	nd	nd	nd	nd
6	2.43 (br d, 17)	nd	nd	nd	nd	nd	nd
	2.4 (m)	nd	nd	nd	nd	–	–
9	2.4 (m)	nd	nd	nd	nd	nd	nd
	2.4 (m)	nd	nd	nd	nd	nd	nd
10	nd	nd	nd	nd	nd	nd	nd
12	7.03 (br s)	7.00 (m)	6.87 (m)	6.91 (m)	6.90 (m)	6.97 (m)	6.92 (q, 1)
13	1.81 (d, 1)	1.86 (d, 1)	1.84 (d, 1)	1.86 (d, 1.5)	1.85 (d, 1)	1.88 (d, 1.5)	1.91 (d, 1)
14	0.86 (s)	0.86 (s)	0.85 (s)	0.94 (s)	0.93 (s)	0.64 (s)	0.64 (s)
15	0.84 (d, 7)	1.10 (d, 7)	1.08 (d, 7)	0.94 (d, 7)	0.94 (d, 7)	0.99 (d, 7)	1.07 (d, 7)
[α]_D (solvent)	nd	+67 (M)	nd	−22 (M)	nd	nd	nd
Source of compound	S. greyi	Synthetic	Synthetic	Synthetic	Synthetic	Synthetic	Synthetic
Ref	8	9, 10	11	9	11	10, 12	10, 13

Abbreviation: nd, not displayed.

Data in ref. 8, [α]_D +53 (CHCl₃), +78 (MeOH) prepared from furanoligularenone.

Probably CDCl₃ by analogy.

Discussion

The data of 10βH-furanoeremophilan-3α-ol (1),⁶ 10αH-furanoeremophilan-3β-ol (2),^7-9 10βH-furanoeremophilan-3β-ol (3),^7,9 and 10αH-furanoeremophilan-3-one (4)^8,10,11 (Figure 2) are listed in Table 1. Both 10αH- and 10βH-furanoeremophilan-3β-ols have been reported.^7-9 Compounds 1 and 3 are C-3 epimers. The data are relatively old and full assignment has not been reported for compounds 1-4. Furanoligularanol (2) is found in nature and also synthesized by hydrogenation of furanoligularenone.^7-9 The specific rotation of natural compound 2 is reported to be [α]_D +53 (CDCl₃) in reference 8, and the one prepared from furanoligularenone +78 (MeOH).⁸

Table 2 shows the data of 10βH-2β-angeloyloxyfuranoeremophilane (5),^12,13 10βH-2β-senecioyloxyfuranoeremophilane (6),¹³ and 10βH-2β-(5'-hydroxyangeloyloxy)furanoeremophilane (7)¹² (Figure 2). Compounds 5 and 7 were measured at 77 °C in C₆D₆, probably due to broadening of some peaks. The ¹³C NMR data of compound 5 in reference 13 showed only 19 carbons; presumably the resonance at δ 35.8 corresponds to 2 carbons for C-1 and C-10. Only 18 carbons were listed for compound 6 in reference 13; it can be considered that the resonances of 2 carbons C-5 and C-10 are likely overlapped at δ 22.8 (C-5 and 4') and 35.7 (C-1 and 10), respectively.

Table 2.

Data of Compounds 5-7.

Compound	5	5	5	5		6	6		7
(solvent)	¹H (B)^a^,^b	¹H (T)	¹H (C)	¹H (B)	¹³C (B)^c	¹H (C)	¹H (B)	¹³C (B)^c	¹H (B)^a^,^b
1	nd	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	35.8	1.2-2.7 (m)	1.1-2.6 (m)	35.7	nd
	nd	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	–	1.2-2.7 (m)	1.1-2.6 (m)	–	nd
2	5.19 (dddd, 8, 8, 3, 3)	5.07 (m)	5.17 (m)	5.15 (m)	69.8	5.16 (m)	5.18 (m)	69.1	5.19 (dddd, 8, 8, 3, 3)
3	nd	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	34.6	1.2-2.7 (m)	1.1-2.6 (m)	34.6	nd
	nd	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	–	1.2-2.7 (m)	1.1-2.6 (m)	–	nd
4	1.60 (m)	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	32.7	1.2-2.7 (m)	1.1-2.6 (m)	32.7	1.60 (m)
5	–	–	–	–	22.8	–	–	(22.8)^f	–
6	2.45 (d, 14)	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	30.0	1.2-2.7 (m)	1.1-2.6 (m)	30.0	2.43 (d, 14)
	1.9 (m)	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	–	1.2-2.7 (m)	1.1-2.6 (m)	–	1.9 (m)
7	–	–	–	–	119.5	–	–	119.6	–
8	–	–	–	–	148.5	–	–	148.7	–
9	2.58 (br dd, 17, 7)	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	26.4	1.2-2.7 (m)	1.1-2.6 (m)	26.4	2.57 (br dd, 17, 7)
	2.44 (br dd, 17)	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	–	1.2-2.7 (m)	1.1-2.6 (m)	–	2.44 (br dd, 17)
10	nd	1.3-2.3 (m)	1.3-2.3 (m)	1.3-2.3 (m)	(35.8)^d	1.2-2.7 (m)	1.1-2.6 (m)	(35.8)^f	nd
11	–	–	–	–	115.5	–	–	115.6	–
12	7.04 (br s)	6.87 (m)	7.04 (m)	7.02 (m)	137.7^e	7.03 (m)	7.01 (m)	137.7	7.04 (br s)
13	1.83 (d, 1)	1.87 (d, 1.3)	1.90 (d, 1.3)	1.79 (d, 1.3)	8.1	1.90 (d, 1.1)	1.78 (d, 1.1)	8.2	1.84 (d, 1)
14	0.86 (s)	0.99 (s)	1.00 (s)	0.79 (s)	15.8	1.00 (s)	0.80 (s)	16.9	0.87 (s)
15	0.84 (d, 7)	0.96 (d, 7.0)	0.96 (d, 7.0)	0.81 (d, 7.0)	17.0	0.93 (d, 7.0)	0.81 (d, 7.0)	20.0	0.82 (d, 7)
1'	–	–	–	–	166.6	–	–	165.6	–
2'	–	–	–	–	128.7	–	–	117.2	–
3'	5.79 (qq)	5.92 (qd, 6.9, 1.2)	6.03 (qd, 6.9, 1.2)	5.74 (qd, 6.9, 1.2)	137.7^e	5.66 (m)	5.76 (m)	155.6	6.03 (tq)
4'	2.00 (dq)	1.97 (dq, 6.9, 1.4)	1.98 (dq, 6.9, 1.4)	2.01 (dq, 6.9, 1.4)	22.7	1.89 (d, 1.2)	1.47 (d, 1.2)	22.8	1.99 (tq)
5'	1.91 (dq)	1.85 (m)	1.90 (m)	1.89 (m)	21.0	2.17 (d, 1.2)	2.16 (d, 1.2)	27.0	4.21 (br s) 2H
[α]_D (solvent)	−26.9 (C)	−33.5 (C)	−33.5 (C)	−33.5 (C)		−51.3 (C)	−51.3 (C)		−32.7 (C)
Source of compound	S. alatus	P. niveus	P. niveus	P. niveus		P. niveus	P. niveus		S. alatus
Ref	12	13	13	13		13	13		12

Abbreviation: nd, not displayed.

J not shown.

Measured at 77°C.

Tentative.

Only 19 carbons shown (likely C-10 35.8).

May be interchanged.

Only 18 carbons shown (likely C-5 22.8 and C-10 35.7).

Table 3 compiles the data of five 3-acyloxyfuranoeremophilanes, 8-12 (Figure 2).^6,7,14-16 Compounds 8-11 have 10βH, while 12 10αH. Unfortunately, the data of H-10 have not been reported for these compounds. The acyl groups of these compounds are different from each other. There are 2 hydrogen atoms at C-6 and C-9, but only 1 proton is shown for compound 9,¹⁵ unfortunately. Compound 11 was measured in C₆D₆ at 73 °C.⁶

Table 3.

Data of Compounds 8−12.

Compound	8	9	9	9	10	11	11	12
(solvent)	¹H (T)	¹H (T)	¹H (B)	¹H (C)	¹H (C)	¹H (C)	¹H (B)^b	¹H (C)
1	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd
2	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd
3	5.25 (ddd, 10, 5, 5)	5.34 (m)	5.50 (m)	5.24 (ddd, 9.5, 5, 5)	5.17 (m)	–	–	–
4	nd	nd	nd	nd	nd	5.22 (m)	5.16 (ddd, 10, 10, 5)	4.75 (ddd, 10, 10, 4)
6	2.25 (br d, 17)	nd	nd	2.63 (dd, 16.5, 1.3)	2.59 (br d, 17)	2.59 (br d, 17)	2.43 (br d, 17)	nd
	2.75 (br d, 17)	nd	nd	nd	2.10 (m)	2.10 (m)	1.85 (m)	nd
9	nd	nd	nd	nd	2.71 (dm, 17)	2.69 (dm, 17)	2.57 (dd, 17, 7)	nd
	nd	nd	nd	2.73 (br dd, 17, 6)	2.10 (m)	2.10 (m)	2.44 (br d, 17)	nd
10	nd	nd	nd	nd	nd	nd	nd	nd
12	6.92 (br s)	7.04 (m)	7.13 (m)	7.04 (q, 1)	7.06 (br s)	7.06 (br s)	7.03 (br s)	6.92 (br s)
13	1.09 (d, 1)	1.88^a	1.77 (d, 1)	1.93 (d, 1)	1.92 (br s)	1.92 (br s)	1.81 (d, 1)	1.89 (d, 1)
14	0.93 (s)	0.90 (s)	0.73 (s)	1.04 (s)	1.01 (br s)	1.01 (br s)	0.83 (s)	0.73 (s)
15	0.99 (d, 7)	0.97 (d, 7)	0.92 (d, 7)	1.00 (d, 7)	1.01 (br s)	1.01 (br s)	0.84 (d, 7)	0.96 (d, 7)
2'	–	–	–	–	–	–	–	5.56 (q, 1)
3'	5.45 (dq, 1.7, 1.7)	6.01 (q, 8)	5.81 (q, 8)	6.04 (qq, 7, 1)	6.86 (qq, 7, 1)	6.98 (q,7)	6.88 (q, 7)	–
	6.03 (dq, 1.7, 1)	–	–	–	–	–	–	–
4'	1.91 (dd, 1.7, 1)	1.99^a	2.03 (d, 8)	2.01 (dq, 7, 1)	1.81 (dq, 7, 1)	1.93 (d, 7)	1.51 (d, 7)	2.17 (q, 7) 2H
5'	–	1.88^a	1.92 (q, 1)	1.93 (dq, 1, 1)	1.85 (dq, 1,1)	4.38 (d, 6) 2H	4.34 (br s) 2H	1.09 (t, 7)
6'	–	–	–	–	–		–	2.14 (d, 1)
[α]_D (solvent)	nd	−38 (M)	nd	nd	nd	nd	nd	nd
Source of compound	Othonna macrophylla	F. japonicum	F. japonicum	Othonna filicaulis	S. greyi	S. greyi	S. greyi	S. praecox
Ref	14	7	7	15	6	6	6	16

Abbreviation: nd, not displayed.

Shape and J not shown.

Measured at 73°C.

The data of two 2,3-dihydroxyfuranoeremophilanes, 13 and 14,¹⁵ and three 3,6-dihydroxyfuranoeremophilanes, 15-17,^17-21 (Figure 3) are presented in Table 4. The configurations at C-3 and C-10 of compounds 13 and 14 are different. Compounds 15 and furanofukinol (16) are C-3 epimers, while furanofukinol (16) and 17 C-6 epimers. The configuration at C-3 of furanofukinol (16) was previously assigned 3α-OH,¹⁹ but later revised to 3β-OH as depicted in structure 16.^17,20

Figure 3.

Compounds 13-19.

Table 4.

Data of Compounds 13-17.

Compound	13	14	15	16	16	16		17
(solvent)	¹H (T)	¹H (C)	¹H (D)	¹H (D)	¹H (D)	¹H (C)	¹³C (P)	¹H (D)
1	nd	nd	nd	nd	nd	nd	27.0	nd
	nd	nd	nd	nd	nd	nd	–	nd
2	3.65 (m)	4.03 (m)	nd	nd	nd	nd	28.2	nd
	–	–	nd	nd	nd	nd	–	nd
3	3.65 (m)	4.03 (m)	nd	nd	nd	4.21 (ddd, 10, 5, 5)	68.1	nd
4	nd	nd	nd	–	–	–	39.3	nd
5	–	–	–	–	–	–	43.0	–
6	nd	nd	nd	nd	nd	4.90 (br s)	66.8	4.70 (d, 7)
7	–	–	–	–	–	–	121.4	–
8	–	–	–	–	–	–	149.5	–
9	nd	nd	nd	–	–	–	30.4	–
10	nd	nd	nd	nd	nd	nd	37.0	–
11	–	–	–	–	–	–	119.5	–
12	7.00 (br s)	7.05 (br s)	7.14 (m)	nd	nd	nd	138.4	–
13	1.85 (d, 1)	1.89 (d, 1)	1.98 (d, 1)	7.14 (m)	7.16 (br s)	7.06 (q, 1.3)	7.7	1.94 (d, 1)
	–	–	–	1.98 (d, 1)	2.00 (br s)	2.07 (d, 1.3)	–	–
14	0.99 (s)	1.00 (s)	0.77 (s)	0.77 (s)	0.76 (s)	0.95 (s)	9.1	0.73 (s)
15	0.89 (d, 6.5)	1.11 (d, 6.5)	0.84 (d, 7)	0.84 (d, 7)	0.84 (d, 7)	0.97 (d, 7.3)	20.1	0.91 (d, 7)
OH	–	–	–	–	–	–	–	4.09 (d, 5) 3-OH
OH	–	–	–	–	–	–	–	4.87 (d, 7) 6-OH
[α]_D (solvent)	nd	nd	nd	nd	nd	−18 (dioxane)		nd
Source of compound	Synthetic	Synthetic	Synthetic	Synthetic	Synthetic	P. japonicus		Synthetic
Ref	15	15	17	17	18	19, 20		21

Abbreviation: nd, not displayed.

The data of two 3,9-diols, 18 and 19^7,9 (Figure 3), and four 2,3-diol monoacyloxy derivatives, 20-23¹⁵ (Figure 4) are provided in Table 5. Compounds 18 and 19 are C-9 epimers.^7,9 The ¹H NMR spectrum of compound 18 was measured in CD₃OD, while 19 in CDCl₃, and the shape of H-9 of 18 was multiplet, while that of 19 singlet. The specific rotation of 18 was not reported, because this was the racemic synthetic product. Compound 20 has 2β,3β-configurations, but compounds 21-23 2β,3α-configurations. Compounds 20 and 22 have angeloyloxy groups, and 21 and 23 senecioyloxy groups. It is interesting to note that H-3 of compound 20 resonates at δ 5.33, rather lower field than other data.

Figure 4.

Compounds 20-34.

Table 5.

Data of Compounds 18-23.

Compound	18	19	20	21	22	23
(solvent)	¹H (M)	¹H (C)	¹H (C)	¹H (T)	¹H (T)	¹H (T)
1	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd
2	nd	nd	4.16 (ddd, 6.5, 3, 3)	3.81 (ddd, 9, 9, 6.5)	4.98 (ddd, 9, 9, 6.5)	4.92 (ddd, 9, 9, 6.5)
	nd	nd	–	–	–	–
3	4.15 (m)	4.08 (m)	5.33 (dd, 5.5, 3.5)	–	–	–
	–	–	–	4.73 (dd, 10, 9)	3.47 (dd, 10, 9)	3.44 (dd, 10, 9)
4	nd	nd	nd	nd	nd	nd
6	nd	1.96 (d, 17)	nd	nd	nd	nd
	2.79 (br d, 16)	2.66 (d, 17)	nd	nd	nd	nd
9	4.70 (m)	4.40 (s)	nd	nd	nd	nd
10	nd	nd	nd	nd	nd	nd
12	7.12 (m)	7.12 (q, 1.5)	7.06 (br s)	6.91 (br s)	6.91 (br s)	6.91 (br s)
13	1.87 (d, 1)	1.90 (d, 1.5)	1.90 (d, 1)	1.88 (d, 1)	1.88 (d, 1)	1.88 (d, 1)
14	0.93 (s)	1.14 (s)	1.00 (s)	1.13 (s)	1.06 (s)	1.05 (s)
15	0.97 (d, 7)	1.00 (d, 7)	1.16 (d, 6.5)	0.84 (d, 6.5)	0.96 (d, 6.5)	0.95 (d, 6.5)
2'	–	–	–	5.61 (qq, 1, 1)	–	5.63 (qq, 1, 1)
3'	–	–	6.14 (qq, 7, 1)	–	6.00 (qq, 7, 1)	–
4'	–	–	2.05 (dq, 7, 1)	1.89 (d, 1)	1.97 (dq, 7, 1)	1.89 (d, 1)
5'	–	–	2.00 (dq, 1, 1)	2.17 (d, 1)	1.87 (dq, 1, 1)	2.2 (d, 1)
[α]_D (solvent)	nd	−24 (E)	nd	nd	nd	nd
Source of compound	Synthetic	Synthetic	Synthetic	Synthetic	Synthetic	Synthetic
Ref	9	7	15	15	15	15

Abbreviation: nd, not displayed.

Table 6 tabulates the data of 6β-ethoxyfuranoeremophilan-3β-ol, 24,¹³ 6β-acetoxyfuranoeremophilan-3α-ol 25,²² and three 6β-acyloxy-3-ols, 26-28 (Figure 4).^20,22-25 Unfortunately, only H-6 and acetyl protons were reported for compound 25.²² Coupling constants for a 2-methylbutanoyl group of compound 26 were not described.²³

Table 6.

Data of Compounds 24-28.

Compound	24	24	25	26	27	28	28	28
(solvent)	¹H (C)	¹H (B)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹³C (C)
1	nd	nd	nd	nd	nd	nd	nd	nd	27.5
	nd	nd	nd	nd	nd	nd	nd	nd	–
2	nd	nd	nd	nd	nd	nd	nd	nd	26.9
	nd	nd	nd	nd	nd	nd	nd	nd	–
3	4.23 (m)	3.83 (m)	nd	4.35 (ddd, 9, 4, 4)	4.40 (m)	4.40 (ddd, 10, 5, 4)	4.36 (ddd, 10, 5, 5)	4.40 (ddd, 10.5, 5.5, 5.5)	68.9
4	nd	nd	nd	2.04 (m)	nd	nd	nd	nd	39.2
5	–	–	–	–	–	–	–	–	42.0
6	4.50 (m)	4.31 (m)	6.34 (s)	6.36 (br s)	6.50 (s)	6.46 (br s)	6.40 (br s)	6.50 (s)	68.5
7	–	–	–	–	–	–	–	–	115.2
8	–	–	–	–	–	–	–	–	150.4
9	2.18 (m)	2.06 (m)	nd	2.26 (br d, 17)	nd	2.88 (dd, 17, 5)	2.32 (br d, 17)	nd	28.9
	2.79 (m)	2.63 (m)	nd	2.87 (br dd, 17, 6)	nd	nd	2.85 (br dd, 17, 5)	nd	–
10	nd	nd	nd	1.8 (m)	nd	nd	nd	nd	36.9
11	–	–	–	–	–	–	–	–	119.6
12	7.01 (m)	7.01 (m)	nd	7.05 (br s)	nd	7.05 (br s)	7.02 (br s)	7.07 (q, 1.2)	138.8
13	2.03 (d, 1.2)	1.99 (d, 1.2)	nd	1.86 (d, 1)	nd	1.82 (d, 1)	1.81 (d, 1)	1.83 (d, 1.2)	7.0
14	0.99 (s)	1.03 (s)	nd	1.06 (s)	nd	1.03 (s)	0.98 (s)	1.03 (s)	20.4
15	0.98 (d, 7.0)	0.87 (d, 7.0)	nd	1.01 (d, 7)	nd	0.96 (d, 7)	0.95 (d, 7)	0.95 (d, 6.0)	8.5
1'	3.76 (q, 7.1)	3.54 (q, 7.1)	–	–	–	–	–	–	168.1
	3.77 (q, 7.1)	3.55 (q, 7.1)	–	–	–	–	–	–	–
2'	1.26 (t, 7.1)	1.13 (t, 7.1)	–	2.45 (tq)^a	–	–	–	–	127.8
3'	–	–	–	nd	nd	6.15 (qq, 7, 1)	6.10 (qq, 7, 1.5)	6.14 (q, 7.0)	138.4
4'	–	–	–	1.02 (t)^a	nd	2.04 (dq, 7, 1)	2.01 (dq, 7, 1.5)	2.02 (br d, 7.5)	20.7
5'	–	–	–	1.24 (d)^a	nd	1.94 (dq, 1, 1)	1.92 (dq, 1.5, 1.5)	1.98 (br s)	16.0
OH/OAc	–	–	2.18 (s)	–	2.70 (s)	–	–	–	–
[α]_D (solvent)	nd	nd	nd	nd	nd	nd	nd	−41.4 (C)
Source of compound	synthetic	synthetic	P. japonicus	synthetic	P. japonicus	Gynoxys sancto antonii	S. pyramidatus	P. japonicus
Ref	13	13	22	23	22	24	25	20

Abbreviation: nd, not displayed.

J not shown.

Table 7 gives the data of two 6β-acyloxy-3β-ols, 29 and 30,^13,14 three 3-acyloxy-6β-ols, 31-33,^15,17,26 and 3β-angeloyloxyfuranoeremophilan-9β-ol 34 (Figure 4).⁷ Compounds 29 has a tigloyloxy group at C-6, while 30 a senecioyloxy group. Compounds 32 and 33 are C-3 epimers. Because H-3 of compounds 29-31 and 33 have at least one large coupling, these molecules seem to adopt non-steroid-like conformations (vide infra).

Table 7.

Data of Compounds 29-34.

Compound	29	29	30 ^a	31	32	33	34	34
(solvent)	¹H (T)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹H (T)	¹H (B)
1	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd
2	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd
3	4.38 (ddd, 10, 5, 5)	4.39 (ddd, 10, 5, 5)	4.38 (ddd, 10, 5, 5)	5.30 (ddd, 12, 4, 3)	5.30 (m)	5.36 (ddd, 10.5, 5, 5)	5.16 (m)	5.32 (quint, 5)^a
4	–	–	–	nd	nd	nd	nd	nd
5	nd	nd	nd	–	–	–	nd	nd
6	6.40 (br s)	6.38 (m)	6.40 (br s)	4.99 (br s)	5.07 (br s)	5.05 (br s)	nd	nd
9	nd	2.20 (m)	nd	2.83 (br dd, 17, 6)	nd	nd	4.30 (s)	4.23 (s)
	nd	2.86 (m)	nd	2.24 (br d, 17)	nd	2.85 (br dd, 7.15, 6)	–	–
10	nd	nd	nd	2.07 (m)	nd	nd	nd	nd
12	7.03 (br s)	7.00 (m)	7.03 (br s)	7.05 (br s)	7.04 (m)	7.04 (br s)	7.00 (m)	6.98 (m)
13	1.81 (d, 1)	1.79 (d, 1.1)	1.81 (d, 1)	2.07 (br s)	1.8-2.1 (m)	2.07 (d, 1)	1.89	1.70 (d, 1)
14	0.97 (s)	1.02 (s)	0.97 (s)	0.95 (s)	0.95 (s)	0.98 (s)	1.10 (s)	1.07 (s)
15	0.94 (d, 7)	0.95 d, 7.0)	0.94 (d, 7)	0.99 (d, 7)	1.00 (d, 7)	1.01 (d, 7)	0.98 (d, 7)	0.94 (d, 7)
2'	–	–	5.75 (qq, 1.5, 1.5)	–	–	–	–	–
3'	6.92 (qq, 7, 1)	6.88 (q, 6.4)	–	6.11 (br s)	6.05 (m)	6.05 (qq, 7, 1)	5.93 (q, 7)	5.70 (q, 7)
				5.56 (dq, 1.5, 1.5)	–	–	–	–
4'	nd	1.84 (d, 6.4)	2.20 (d, 1.5)	1.95 (dd, 1.5, 1.5)	1.8-2.1 (m)	1.99 (dq, 7, 1)	1.96 (d, 7)	2.03 (d, 7)
5'	nd	1.87 (br s)	1.91 (d, 1.5)	–	1.8-2.1 (m)	1.91 (dq, 1, 1)	1.89 (m)	1.89 (m)
[α]_D (solvent)	nd	nd	nd	nd	nd	nd	−11 (M)	−11 (M)
Source of compound	Synthetic	Synthetic	Synthetic	Lopholaena coriifolia, Lopholaena segmentata	F. hiberniflorum	Othonna filicaulis	F. japonicum	F. japonicum
Ref	14	13	14	26	17	15	7	7

Abbreviation: nd, not displayed.

Data mixture with compound 29.

Tentative.

The data of five 3β-acyloxy-6β-alkoxyfuranoeremophilanes, 35-39 (Figure 5)¹³ are found in Table 8. Compounds 35 and 36 are isomers of 6β-alkoxy groups. Compounds 35 and 37, and 36 and 38 are isomers of 3β-acyloxy groups. Compound 39 have a benzyl group at C-6. Five aromatic protons of compound 39 appeared at δ 7.34 (m) in CDCl₃ and δ 7.15 (m) in C₆D₆.¹³ The ¹³C NMR data of compound 38 in C₆D₆ have been tentatively assigned.

Figure 5.

Compounds 35-45.

Table 8.

Data of Compounds 35-39.

Compound	35	36	36		37	38	38		39	39
(solvent)	¹H (B)	¹H (C)	¹H (B)	¹³C (B)^a	¹H (B)	¹H (C)	¹H (B)	¹³C (B)^a	¹H (C)	¹H (B)
1	1.10-2.20 (m)	1.20-2.30 (m)	1.16-2.18 (m)	26.4	1.05-2.84 (m)	1.20-2.30 (m)	1.15-2.10 (m)	26.5	nd	nd
	1.10-2.20 (m)	1.20-2.30 (m)	1.16-2.18 (m)	–	1.05-2.84 (m)	1.20-2.30 (m)	1.15-2.10 (m)	–	nd	nd
2	1.10-2.20 (m)	1.20-2.30 (m)	1.16-2.18 (m)	36.6	1.05-2.84 (m)	1.20-2.30 (m)	1.15-2.10 (m)	36.6	nd	nd
	1.10-2.20 (m)	1.20-2.30 (m)	1.16-2.18 (m)	–	1.05-2.84 (m)	1.20-2.30 (m)	1.15-2.10 (m)	–	nd	nd
3	5.40 (m)	5.39 (m)	5.43 (m)	72.1	5.39 (m)	5.33 (m)	5.46 (m)	71.2	5.42 (m)	5.71 (m)
4	1.10-2.20 (m)	1.20-2.30 (m)	1.16-2.18 (m)	36.1	1.05-2.84 (m)	1.20-2.30 (m)	1.15-2.10 (m)	36.2	nd	nd
5	–	–	–	43.5	–	–	–	43.5	–	–
6	4.50 (m)	4.61 (m)	4.65 (m)	76.2	4.43 (m)	4.60 (m)	4.65 (m)	76.1	4.76 (m)	4.72 (m)
7	–	–	–	120.6	–	–	–	120.5	–	–
8	–	–	–	149.4	–	–	–	149.2	–	–
9	2.25 (dd, 17.0, 1.5)	2.23 (dd, 17.0, 1.5)	2.09 (dd, 17.0, 1.5)	26.7	1.05-2.84 (m)	2.19 (m)	2.05 (m)	26.7	nd	nd
	2.78 (ddd, 17.0, 6.1, 2.2)	2.80 (ddd, 17.0, 6.0, 2.2)	2.60 (ddd, 17.0, 6.0, 2.2)	–	1.05-2.84 (m)	2.78 (ddd, 17.0, 6.1, 2.2)	2.65 (ddd, 17.0, 6.1, 2.2)	–	nd	nd
10	1.10-2.20 (m)	1.20-2.30 (m)	1.16-2.18 (m)	27.2	1.05-2.84 (m)	1.20-2.30 (m)	1.15-2.10 (m)	27.4	nd	nd
11	–	–	–	118.3	–	–	–	118.3	–	–
12	7.02 (m)	7.04 (m)	7.03 (m)	137.6	6.97 (m)	7.03 (m)	7.04 (m)	138.5	7.01 (m)	7.00 (m)
13	2.03 (d, 1.1)	2.04 (d, 1.3)	2.00 (d, 1.3)	9.5	2.00 (d, 1.2)	2.03 (d, 1.2)	2.01 (d, 1.2)	9.5	2.03 (d, 1.2)	1.98 (d, 1.2)
14	0.97 (s)	0.99 (s)	1.01 (s)	20.0	1.00 (s)	0.97 (s)	1.03 (s)	20.0	1.08 (s)	1.04 (s)
15	0.96 (d, 7.0)	0.99 (d, 7.1)	0.88 (d, 7.1)	8.6	0.93 (d, 7.2)	0.95 (d, 7.1)	0.99 (d, 7.1)	8.4	0.96 (d, 7.2)	0.84 (d, 7.2)
1'	–	–	–	166.9	–	–	–	165.6	–	–
2'	–	–	–	128.7	5.73 (m)	5.70 (m)	5.81 (m)	117.0	–	–
3'	6.02 (qq, 6.9, 1.1)	6.05 (qq, 6.9, 1.1)	5.69 (qq, 6.9, 1.1)	138.6	–	–	–	155.8	6.02 (qd)	5.45 (qd)
4'	1.90 (m)	1.99 (dq, 6.9, 1.4)	2.00 (dq, 6.9, 1.4)	15.9	2.14 (d, 1.1)	1.89 (d, 1.2)	1.45 (d, 1.2)	27.0	1.96 (dq)	nd
5'	1.95 (dq, 6.9, 1.4)	1.94 (m)	1.94 (m)	21.0	1.47 (d, 1.0)	2.17 (d, 1.2)	2.13 (d, 1.2)	nd	1.93 (m)	nd
1''	3.70 (s)	3.92 (q, 7.0)	4.05 (q, 7.0)	68.8	3.71 (s)	3.89 (q, 7.0)	4.10 (q, 7.0)	68.7	4.93 (s)	4.87 (d, 11)
	–	3.91 (q, 7.0)	3.85 (q, 7.0)	–	–	3.88 (q, 7.0)	3.87 (q, 7.0)	–	4.93 (s)	5.15 (d, 11)
2''	–	1.26 (t, 7.0)	1.22 (t, 7.0)	16.1	–	1.25 (t, 7.0)	1.24 (t, 7.0)	16.0	7.34 (m)^b	7.15 (m)^b
[α]_D (solvent)	nd	−25.7 (C)	−25.7 (C)		nd	−25.2 (C)	−25.2 (C)		nd	nd
Source of compound	Synthetic	P. niveus	P. niveus		Synthetic	P. niveus	P. niveus		Synthetic	Synthetic
Ref	13	13	13		13	13	13		13	13

Abbreviation: nd, not displayed.

Tentative.

For -C₆H₅.

Table 9 lists the data of six 2,3-diacyloxyfuranoeremophilanes, 40-45¹⁵ (Figure 5) and 3β,6β-diacetoxyfuranoeremophilane (46)^20,21 (Figure 6). Compounds 40-42 are monoacetates, and 46 is diacetate. Compounds 40 and 41 have angeloyloxy groups, and 43 and 44 bis(angeloyloxy) groups. Compound 45 has an angeloyloxy group at C-2 and a senecioyloxy group at C-3. The data of an acetyl group of compound 40 is not described.¹⁵

Figure 6.

Compounds 46-62.

Table 9.

Data of Compounds 40-46.

Compound	40	41	42	43	44	45	46	46
(solvent)	¹H (C)	¹H (T)	¹H (T)	¹H (T)	¹H (C)	¹H (T)	¹H (C)	¹H (C)
1	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd
2	5.38 (m)	5.08 (m)	5.05 (m)	5.20 (m)	5.40 (m)	5.15 (m)	nd	nd
	–	–	–	–	–	–	nd	nd
3	5.38 (m)	5.08 (m)	5.05 (m)	5.20 (m)	5.40 (m)	5.15 (m)	5.32 (m)	5.28 (ddd, 10, 5.5, 5.5)
4	nd	nd	nd	nd	nd	nd	nd	nd
6	nd	nd	nd	nd	nd	nd	6.37 (br s)	6.28 (s)
9	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd
10	nd	nd	nd	nd	nd	nd	nd	nd
12	7.04 (br s)	6.92 (br s)	6.92 (br s)	6.93 (br s)	7.04 (br s)	6.92 (br s)	7.06 (m)	6.98 (q, 1.1)
13	1.90 (d, 1)	1.88 (d, 1)	1.88 (d, 1)	1.88 (d, 1)	1.90 (d, 1)	1.89 (d, 1)	1.88 (d, 1)	1.82 (d, 1.1)
14	1.02 (s)	1.17 (s)	1.16 (s)	1.18 (s)	1.00 (s)	1.17 (s)	1.01 (s)	0.98 (s)
15	1.15 (d, 6.5)	0.82 (d, 6.5)	0.82 (d, 6.5)	0.83 (d, 6.5)	1.14 (d, 6.5)	0.82 (d, 6.5)	0.97 (d, 7)	0.93 (d, 6.0)
2'	nd	–	5.56 (qq, 1, 1)	–	–	–	2.03 (s) 3-OAc	2.00 (s) OAc
3'	–	5.98 (qq, 7, 1)	–	5.94 (m)	6.08 (qq, 7, 1)	5.94 (qq, 7, 1)	–	–
4'	–	1.96 (dq, 7, 1)	1.89 (d, 1)	1.94 (dq, 7, 1)	2.00 (dq, 7, 1)	1.8-2.0 (m)	–	–
5'	–	1.82 (dq, 1, 1)	2.14 (d, 1)	1.8-1.9 (m)	1.89 (br s)	1.8-2.0 (m)	–	–
2''	–	1.92 (s) OAc	1.91 (s) OAc	–	–	5.55 (qq, 1, 1)	2.13 (s) 6-OAc	2.11 (s) OAc
3''	6.09 (qq, 7, 1)	–	–	5.94 (m)	6.08 (qq, 7, 1)	–	–	–
4''	2.01 (dq, 7, 1)	–	–	1.8-1.9 (m)	2.00 (dq, 7, 1)	1.8-2.0 (m)	–	–
5''	1.89 (dq, 1, 1)	–	–	1.94 (dq, 7, 1)	1.89 (br s)	2.12 (d, 1)	–	–
[α]_D (solvent)	nd	nd	−15.3 (C)	nd	nd	nd	nd	−53.7 (C)
Source of compound	Othonna bulbosa	Othonna bulbosa	Othonna bulbosa	Othonna bulbosa	Othonna bulbosa	Othonna bulbosa	Synthetic	Synthetic
Ref	15	15	15	15	15	15	21	20, 21

Abbreviation: nd, not displayed.

Table 10 compiles the data of nine 3,6-diacyloxy compounds, 47-55 (Figure 6).^15,23-25,27 Compounds 47-50 have 3β-acetoxy groups, while 51-55 6β-acetoxy groups. Compounds 52 and 53 are C-3 epimers. The data of an acetyl group of compounds 51-55 are not described. Only a part of ¹H NMR data were reported for compound 51.²⁷ The H-3 of compounds 52, 54, and 55 appear as (ddd, 10, 10, 5) indicating that these molecules adopt steroid-like conformations (vide infra).

Table 10.

Data of Compounds 47-55.

Compound	47	48	49	50	51	52		52	53	54	55
(solvent)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹H (C)^a	¹H (C)	¹H (B)	¹H (C)^a	¹H (C)^a,b	¹H (C)^a	¹H (C)^a
1	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd
2	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd
3	5.27 (ddd, 9, 4, 4)	5.34 (ddd, 10, 5, 5)	5.34 (ddd, 10, 5, 5)	5.34 (ddd, 10, 5, 5)	5.36 (ddd, 10, 5, 5)	5.37 (m)	5.57 (m)	4.68 (ddd, 10, 10, 5)	5.40 (ddd, 9.5, 4.5, 4.5)	4.65 (ddd, 10, 10, 5)	4.66 (ddd, 10, 10, 5)
4	2.10 (m)	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd
6	6.35 (br s)	6.47 (br s)	6.43 (br s)	6.40 (br s)	6.35 (br s)	6.37 (br s)	6.51 (br s)	6.36 (br s)	6.37 (br s)	6.35 (br s)	6.35 (br s)
9	2.32 (br d, 17)	2.31 (br d, 17)	2.31 (br d, 17)	2.31 (br d, 17)	2.84 (dd, 17)	nd	nd	2.58 (br d, 17)	2.29 (br d, 17)	2.58 (br d, 17)	2.58 (br d, 17)
	2.84 (br dd, 17, 6)	2.87 (br dd, 17, 5)	2.87 (br dd, 17, 5)	2.85 (br dd, 17, 5)	2.34 (br d, 17)	nd	nd	nd	2.84 (br dd)	nd	nd
10	1.88 (m)	nd	nd	nd	nd	nd	nd	nd	nd	nd	nd
12	7.04 (br s)	7.04 (br s)		7.04 (br s)	nd	7.05 (m)	6.95 (m)	7.04 (br s)	7.01 (br s)	7.04 (br s)	7.04 (br s)
13	1.87 (d, 1)	1.85 (d, 1)	1.80 (d, 1)	1.84 (d, 1)	nd	1.87 (d, 1.5)	1.8-2.2 (m)	1.86 (d, 1)	1.88 (d)	1.86 (d, 1)	1.86 (d, 1)
14	1.05 (s)	1.04 (s)	1.03 (s)	1.00 (s)	1.03 (s)	1.03 (s)	0.95 (s)	1.02 (s)	1.03 (s)	1.02 (s)	1.03 (s)
15	0.95 (d, 7)	0.95 (d, 7)	0.95 (d, 7)	0.94 (d, 7)	0.99 (d, 7)	0.97 (d, 7)	0.90 (d, 7)	1.04 (d, 7)	0.93 (d)	1.04 (d, 7)	1.05 (d, 7)
2'	2.42 (tq)	–	–	5.73 (qq, 1.5, 1.5)	–			–	–	–	5.65 (qq, 1)
3'	–	6.10 (qq)	6.91 (qq, 7, 1.5)	–	nd	6.01 (br q, 7)	5.57 (m)	6.04 (qq, 7, 1)	6.00 (qq, 7, 1)	6.84 (qq, 7, 1)	–
4'	0.94 (t)	2.02 (dq)	1.80 (dq, 7, 1.5)	2.01 (d, 1.5)	nd	1.97 (br d, 7)	1.8-2.2 (m)	1.96 (dq, 7, 1)	1.97 (dq, 7, 1)	1.72 (br s)	1.87 (d, 1)
5'	1.22 (d)	1.93 (dq)	1.88 (dq, 1.5, 1.5)	1.91 (d, 1.5)	nd	1.87 (s)	1.8-2.2 (m)	1.88 (dq, 1, 1)	1.88 (dq, 1, 1)	1.72 (br s)	2.14 (d, 1)
2''	2.04 (s)	–	–	–	nd	2.12 (s)	1.76 (s)	nd	nd	nd	nd
[α]_D (solvent)	nd	nd	−47 (C)	nd	−25.2 (nd)	nd		nd	nd	nd	nd
Source of compound	S. medley-woodii	S. pyramidatus	S. pyramidatus	S. pyramidatus	Othonna lobata	F. hiberniflorum		Gynoxys sancto antonii	Othonna filicaulis	Gynoxys sancto antonii	Gynoxys sancto antonii
Ref	23	25	25	25	27	17		24	15	24	24

Abbreviation: nd, not displayed.

Data of OAc not shown.

J not shown.

The data of five 3,6-diacyloxyfuranoeremophilanes, 56-60 (Figure 6)^13,24,26,28 are presented in Table 11. Compounds 56, 57, and 59 are 6β-angeloyloxy compounds, while 60 a 6β-tigloyloxy derivative. Compounds 57 and 58 have 3β-angeloyloxy groups, while 59 and 60 senecioyloxy groups. The specific rotation of compound 56 was quite small (−1 in CHCl₃), therefore, it was measured at 436 nm to show [α]₄₃₆ −88 (CHCl₃).²⁶ Compound 58 is a mixture with compound 59. The H-3 of all compounds (couplings not clear in compound 60; nevertheless similar values expected) show one large coupling, indicating that these compounds adopt non-steroid-like conformations (vide infra).

Table 11.

Data of Compounds 56-60.

Compound	56 ^a	57	57	57	58 ^b	59	59 ^c	60
(solvent)	¹H (C)	¹H (C)	¹H (B)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹H (C)^d	¹³C (C)
1	nd	1.1-2.4 (m)	1.0-2.2 (m)	nd	nd	nd	nd	1.65 (m)	25.7
	nd	1.1-2.4 (m)	1.0-2.2 (m)	nd	nd	nd	nd	1.49 (m)	–
2	nd	1.1-2.4 (m)	1.0-2.2 (m)	nd	nd	nd	nd	1.90 (m)	25.9
	nd	1.1-2.4 (m)	1.0-2.2 (m)	nd	nd	nd	nd	1.65 (m)	–
3	5.41 (ddd, 12, 4, 4)	5.42 (ddd, 10, 5, 5)	5.58 (ddd, 10, 5, 5)	5.43 (ddd, 10, 5, 4)	5.35 (ddd, 10, 5, 5)	5.36 (ddd, 10, 5, 4)	5.35 (ddd, 10, 5, 5)	5.35 (ddd)	71.1
4	nd	1.1-2.4 (m)	1.0-2.2 (m)	nd	nd	nd	nd	1.90 (m)	36.1
5	–	–	–	–	–	–	–	–	41.9
6	6.42 (br s)	6.46 (m)	6.64 (m)	6.48 (br s)	6.35 (m)	6.48 (br s)	6.42 (m)	6.42 (br s)	68.7
7	–	–	–	–	–	–	–	–	115.5
8	–	–	–	–	–	–	–	–	150.5
9	2.87 (br dd, 17, 6)	2.37 (m)	nd	2.86 (dd, 17, 5)	2.31 (m)	2.85 (dd, 17, 5)	2.31 (m)	2.33 (br dd)	25.8
	2.36 (br d, 17)	2.85 (m)	2.55 (m)	nd	2.83 (m)	nd	2.83 (m)	2.85 (br dd)	–
10	2.15 (m)	1.1-2.4 (m)	1.0-2.2 (m)	nd	nd	nd	nd	2.11 (m)	36.6
11	–	–	–	–	–	–	–	–	119.9
12	7.05 (br s)	7.04 (m)	6.90 (m)	7.05 (br s)	7.04 (m)	7.04 (br s)	7.04 (m)	7.03 (br s)	138.2
13	1.18 (br s)	1.91 (d, 1.1)	1.90 (d, 1.1)	1.86 (d, 1)	1.93 (d, 1.1)	1.84 (d, 1)	1.93 (d, 1.1)	1.82 (d)	8.7
14	1.05 (s)	1.07 (s)	0.98 (s)	1.07 (s)	nd	1.05 (s)	nd	1.05 (s)	19.8
15	0.98 (d, 7)	0.99 (d, 7.1)	0.89 (d, 7.1)	0.99 (d, 7)	nd	0.96 (d, 7)	nd	0.96 (d)	8.5
1'	–	–	–	–	–	–	–	–	165.7
2'	–	–	–	–	–	5.66 (qq, 1, 1)	5.62 (m)	6.88 (qq)	116.6
3'	6.14 (br s)	5.95 (qd, 7.0, 1.1)	5.76 (qd, 7.0, 1.1)	6.02 (qq, 7, 1)	5.94 (qd, 6.9, 1.2)	–	–	–	155.8
4'	1.98 (dd, 1.5, 1.5)	1.1-2.4 (m)	1.0-2.2 (m)	1.98 (dq, 7, 1)	nd	1.87 (d, 1)	nd	1.79 (dq)	27.3
5'	–	1.1-2.4 (m)	1.0-2.2 (m)	1.89 (dq, 1, 1)	5.68 (m)	2.16 (d, 1)	nd	1.87 (br s)	20.2
1''	–	–	–	–	–	–	–	–	167.6
2''	–	–	–	–	nd	–	–	–	128.6
3"	6.02 (qq, 7, 1.3)	6.05 (qd, 7.0, 1.1)	5.76 (qd, 7.0, 1.1)	6.09 (qq, 7, 1)	–	6.08 (qq, 7, 1)	6.04 (qd, 6.9, 1.2)	5.65 (qq)	137.2
4"	1.92 (dq, 7, 1.3)	1.1-2.4 (m)	1.0-2.2 (m)	2.02 (dq, 7, 1)	nd	2.02 (dq, 7, 1)	nd	2.16 (d)	14.4
5"	1.88 (dq, 1.3, 1.3)	1.1-2.4 (m)	1.0-2.2 (m)	1.92 (dq, 1, 1)	nd	1.92 (dq, 1, 1)	nd	1.87 (br s)	12.2
[α]_D (solvent)	−1 (C)	−64.3 (C)	−64.3 (C)	−77 (nd)	nd	nd	nd	nd
Source of compound	Lopholaena segmentata	P. niveus	P. niveus	Gynoxys sancto antonii	P. niveus	Gynoxys sancto antonii	P. niveus	Gynoxys acostae
Ref	26	13	13	24	13	24	13	28

Abbreviation: nd, not displayed.

[α]₄₃₆ −88 (C).

Mixture with 59.

Mixture with 58.

J not shown.

Table 12 provides the data of two 3,6-diacyloxyfuranoeremophilanes, 61^13,14 and 62,^20,22 (Figure 6) and 3,9-diacyloxyfuranoeremophilane 63 (Figures 7).⁷ Compound 61 has 2 senecioyloxy groups, while 63 a senecioyloxy and an angeloyloxy group. S-furanopetasitin (62) has an angeloyloxy group at C-6β and a (3'-methylthio)propenoyloxy group at C-3α. Compound 61 from Orthonna intermedia is a mixture with other compounds.¹⁴ Data of compound 61 described in references 13 and 14 are not necessarily the same. More detailed studies are expected in the future.

Figure 7.

Compounds 63-69.

Table 12.

Data of Compounds 61-63.

Compound	61 ^a	61	61		62		63	63
(solvent)	nd	¹H (C)	¹H (B)	¹³C (B)^b	¹H (C)	¹³C (C)	¹H (B)	¹H (T)
1	nd	1.15-2.90 (m)	1.00-2.85 (m)	26.2	nd	25.8	nd	nd
	nd	1.15-2.90 (m)	1.00-2.85 (m)	–	nd	–	nd	nd
2	nd	1.15-2.90 (m)	1.00-2.85 (m)	26.7	nd	26.3	nd	nd
	nd	1.15-2.90 (m)	1.00-2.85 (m)	–	nd	–	nd	nd
3	5.28 (m)	5.37 (ddd, 10, 5, 5)	5.62 (ddd, 10, 5, 5)	67.7	5.40 (ddd, 9.0, 4.5, 4.5)	72.3	5.27 (m)	5.20 (m)
4	nd	1.15-2.90 (m)	1.00-2.85 (m)	36.5	nd	35.9	nd	nd
5	–	–	–	42.0	–	41.7	nd	nd
6	6.32 (br s)	6.40 (m)	6.68 (m)	71.2	6.50 (s)	68.4	nd	nd
7	–	–	–	120.1	–	115.6	–	–
8	–	–	–	150.5	–	150.5	–	–
9	nd	1.15-2.90 (m)	1.00-2.85 (m)	26.3	nd	30.0	5.82 (s)	5.43 (s)
	2.82 (dd, 16, 6)	1.15-2.90 (m)	1.00-2.85 (m)	–	nd	–	–	–
10	nd	1.15-2.90 (m)	1.00-2.85 (m)	36.7	nd	36.5	nd	nd
11	–	–	–	116.1	–	119.8	–	–
12	6.92 (br s)	7.03 (m)	6.99 (m)	138.8	7.08 (q, 1.0)	138.3	6.97 (q, 1.5)	7.06 (q, 1.5)
13	1.92 (d, 1)	1.89 (d, 1.2)	1.97 (d, 1.2)	8.8	1.87 (d, 1.0)	8.5	1.70 (d, 1.5)	1.94 (d, 1.5)
14	1.02 (s)	1.04 (s)	1.06 (s)	20.0	1.07 (s)	19.9	1.12 (s)	1.06 (s)
15	0.96 (d, 7)	0.97 (d, 7.0)	0.96 (d, 7.0)	8.8	0.98 (d, 7.0)	8.8	0.88 (d, 7)	0.99 (d, 7)
1'	–	–	–	165.2	–	165.6	–	–
2'	nd	5.66 (m)	5.66 (m)	117.1	5.82 (d, 11)	113.5	–	–
3'	–	–	–	157.0	7.03 (d, 11)	151.0	5.6 (m)	5.96 (q, 7)
4'	nd	1.85 (m)	1.44 (m)	27.1	–	–	1.96 (d, 7)	1.95 (d, 7)
5'	nd	2.18 (d, 1.3)	2.10 (d, 1.3)	20.3	–	–	1.89 (m)	1.87^c
1''	–	–	–	166.2	–	167.5	–	–
2''	nd	5.73 (m)	5.75 (m)	116.3	–	127.9	5.65 (m)	5.54 (m)
3"	–	–	–	155.4	6.12 (q, 8)	138.1	–	–
4"	nd	1.89 (m)	1.44 (m)	27.0	2.03 (d, 8)	20.7	1.45 (d, 1.5)	1.87 (m)
5"	nd	2.21 (d, 1.2)	2.13 (d, 1.2)	20.3	1.96 (s)	15.8	2.10 (d, 1.5)	2.16 (d, 1.5)
SMe	–	–	–	–	2.38 (s)	19.0	–	–
[α]_D (solvent)	nd	−80.8 (C)	−80.8 (C)		−60.5 (C)		+17 (M)	+17 (M)
Source of compound	Orthonna intermedia	P. niveus	P. niveus		P. japonicus		F. japonicum	F. japonicum
Ref	14	13	13		20, 22		7	7

Abbreviation: nd, not displayed.

Mixture with other compounds.

Tentative.

J not shown.

Table 13 tabulates the data of 6β-ethoxyfuranoeremophilan-3-one (64)²⁹ and three 6β-acyloxyfuranoeremophilan-3-ones, 65-67 (Figure 7).^29,30 All the compounds having 3-oxo groups have been isolated from Ligularia stenoglossa, the data being reported in the meeting, but the data not published in the literature.

Table 13.

Data of Compounds 64-67.

Compound	64	65		65		66		67
(solvent)	¹H (B)	¹H (C)	¹³C (C)	¹H (B)	¹³C (B)	¹H (B)	¹³C (B)	¹H (B)	¹³C (B)
1	1.15 (ddt, 14.3, 7.2, 3.6)	1.81-1.90 (m)	25.9	1.11 (m)	25.8	1.11 (m)	25.8	1.12 (m)	25.8
	1.61 (m)	2.11-2.23 (m)	–	1.63 (m)	–	1.63 (m)	–	1.61 (m)	–
2	1.90 (ddd, 15.1, 11.5, 7.4)	2.38-2.59 (m)	36.3	1.84 (m)	36.2	1.84 (m)	36.2	1.84 (m)	36.2
	2.08 (ddd, 15.1, 6.0, 3.6)	2.29-2.41 (m)	–	2.05 (m)	–	2.05 (m)	–	2.05 (m)	–
3	–	–	211.7	–	209.0	–	209.0	–	209.1
4	1.96 (m)	2.29-2.41 (m)	46.4	1.84 (q, 6.4)	46.2	1.84 (q, 6.4)	46.2	1.86 (q, 6.7)	46.3
5	–	–	43.8	–	43.8	–	43.8	–	43.9
6	3.81 (s)	5.89 (s)	68.4	6.05 (s)	68.6	6.05 (s)	68.7	6.14 (s)	68.7
7	–	–	111.6	–	116.6	–	116.6	–	116.6
8	–	–	152.3	–	152.9	–	152.9	–	152.8
9	2.34 (dd, 17.3, 9.0)	2.83 (dd, 17.4, 6.9)	24.8	2.36 (m)	24.9	2.36 (m)	24.9	2.37 (d, 8.6)	25.0
	2.43 (dd, 17.3, 7.4)	2.91 (dd, 17.4, 10.6)	–	2.36 (m)	–	2.36 (m)	–	2.37 (d, 8.6)	–
10	2.27 (m)	2.45-2.53 (m)	34.2	2.13 (m)	34.4	2.13 (m)	34.4	2.13 (m)	34.8
11	–	–	119.4	–	119.8	–	119.8	–	119.8
12	6.97 (s)	7.09 (s)	138.4	6.91 (s)	138.7	6.91 (s)	138.7	6.89 (s)	138.7
13	1.82 (s)	1.93 (s)	8.1	2.00 (s)	8.4	2.00 (s)	8.4	1.99 (s)	8.4
14	0.96 (s)	0.91 (s)	18.1	0.80 (s)	18.2	0.80 (s)	18.2	0.81 (s)	18.3
15	0.86 (d, 6.8)	0.98 (d, 6.6)	7.9	0.96 (d, 6.4)	8.1	0.96 (d, 6.4)	8.1	0.97 (d, 6.7)	8.3
1'	3.27 (dq, 8.4, 6.9)	–	176.1	–	171.9	–	171.9	–	167.1
	3.48 (dq, 8.4, 6.9)	–	–	–	–	–	–	–	–
2'	1.07 (t, 6.9)	2.29-2.41 (m)	41.3	2.20 (sext, 6.8)	41.5	1.98 (m) 2H	43.5	–	128.0
3'	–	1.37-1.49 (m)	26.6	1.62 (m)	27.1	2.07 (m)	25.7	5.66 (qq, 7.3, 1.5)	138.0
	–	1.60-1.71 (m)	–	1,.29 (dquint, 14.6, 6.8)	–	–	–	–	–
4'	–	0.86 (t, 7.5)	11.6	0.77 (t, 6.8)	11.8	0.80 (d, 6.5)	22.3	1.93 (dq, 7.3, 1.5)	15.8
5'	–	1.14 (d, 7.0)	16.8	1.03 (d, 6.8)	17.0	0.81 (d, 6.5)	22.4	1.77 (quint, 1.5)	20.8
[α]_D (solvent)	−50.4 (E)	−108 (M)		nd		−125.0 (E)		−129.5 (E)
Source of compound	L. stenoglossa	L. oligonema		L. stenoglossa		L. stenoglossa		L. stenoglossa
Ref	29	30		29		29		29

Abbreviation: nd, not displayed.

The data of 3β-hydroxyfuranoeremophilan-6-one (68),¹⁹ 3β-acetoxyfuranoeremophilan-6-one (69)¹⁹ (Figure 7), and euryopsonol (70)^7,31-34 (Figure 8) are found in Table 14. Compound 69 is an acetyl derivative of compound 68. Compound 70 has a trans decalin system with 3α-hydroxy group. The structure of compound 70 was revised from 10βH to 10αH.^31,32 Unfortunately, ¹H NMR data of compound 70 described in the references 7 and 31-33 are not reasonably the same. The H₂-6 of compound 70 in references 31 and 32, were shown to be δ 2.63 (q, 16.0). However, 2 protons do not appear as a quartet with the same chemical shift value; this must be an AB quartet and should be described as 2.90 (d, 16.0) and 2.36 (d, 16.0) (obtained by calculation), respectively.

Figure 8.

Compounds 70-87.

Table 14.

Data of Compounds 68-70.

Compound	68	69	70 ^a	70	70	70
(solvent)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	nd	¹³C (D)
1	nd	nd	nd	nd	nd		19.5
	nd	nd	nd	nd	nd		–
2	nd	nd	nd	nd	nd		34.7
	nd	nd	nd	nd	nd		–
3	3.68 (m)	4.70 (m)	3.50 (td, 10.8, 4.8)	3.88 (m)	3.46 (ddd, 10, 10, 4.5)		69.2
4	nd	nd	nd	nd	nd		49.2
5	–	–	–	–	–		43.2
6	–	–	2.63 (q, 16.0)^b	nd	2.79 (d, 16.5)		34.7
	–	–	2.63 (q, 16.0)^b	nd	2.46 (16.5)		–
7	–	–	–	–	–		136.9
8	–	–	–	–	–		146.0
9	2.59 (dd, 18, 2)	2.60 (dd, 18, 2)	–	–	–		186.1
	3.11 (dd, 18, 6)	3.15 (dd, 18, 6)	–	–	–		–
10	nd	nd	nd	nd	2.40 (dd, 11.5, 4)		54.3
11	–	–	–	–	–		121.2
12	7.09 (m)	7.08 (m)	7.43 (q, 1)	7.32 (q, 1)	7.36 (q)^c		144.7
13	2.20 (d, 1)	2.20 (d, 1)	2.02 (s, 1.2)	1.97 (d, 1)	1.99 (d)^c		7.3
14	1.15 (s)	1.14 (s)	0.82 (s)	1.02 (s)	0.79 (s)		12.8
15	0.99 (d, 7)	1.00 (d, 7)	1.12 (d, 6.5)	1.16 (d, 7)	1.09 (d)^c		10.5
OH/OAc	–	2.03 (s)	1.91 (s) OH	–	–		–
[α]_D (solvent)	nd	nd	−36 (E)	nd	nd	nd
Source of compound	Synthetic	Synthetic	Euryops floribundus	Synthetic	Synthetic	Euryops floribundus
Ref	19	19	31, 32	7	33	34

Abbreviation: nd, not displayed.

Structure revised from 10βH to 10αH.

H-6 may be ABq; better be revised to 2.90 (d, 16.0) and 2.36 (d, 16.0).

J not shown.

The data of two 3-hydroxyfuranoeremophilan-9-ones, 71 and 72 (Figure 8)^7,9,31-34 are given in Table 15. These 2 compounds are isomeric at C-3 and C-10; the former being trans- and the latter cis-fused compound. Epieuryopsonol isolated from Euryops floribundus was previously assigned to have 10βH, but later revised to 10αH depicted as structure 71.^31,32 The H-6 of compound 71 described as 2.57 (d, 16.0) should likely be changed to 2.90 (d, 16.0) and 2.36 (d, 16.0).³¹

Table 15.

Data of Compounds 71 and 72.

Compound	71 ^a	71	71	71	71		72
(solvent)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	nd	¹³C (D)	¹H (C)
1	nd	nd	nd	nd		15.3	nd
	nd	nd	nd	nd		–	nd
2	nd	nd	nd	nd		32.8	nd
	nd	nd	nd	nd		–	nd
3	3.92 (m)	3.88 (m)	3.90 (m)	3.89 (m)		69.1	3.50 (m)
4	nd	nd	nd	nd		45.2	nd
5	–	–	–	–		42.5	–
6	2.57 (d, 16.0)^b	nd	nd	2.38 (d, 16)		35.1	nd
	2.57 (d, 16.0)^b	nd	nd	2.69 (d, 16)		–	nd
7	–	–	–	–		136.3	–
8	–	–	–	–		146.0	–
9	–	–	–	–		186.5	–
10	nd	nd	nd	nd		55.2	nd
11	–	–	–	–		121.0	–
12	7.38 (q, 1)	7.32 (q, 1)	7.35 (q)^c	7.34 (m)		144.3	7.36 (m)
13	1.99 (d, 1.0)	1.97 (d, 1)	1.98 (d)^c	1.98 (d, 1)		7.2	1.98 (d, 1)
14	1.01 (s)	1.02 (s)	1.01 (s)	1.01 (s)		14.0	1.14 (s)
15	1.14 (d, 6.5)	1.16 (d, 7)	1.13 (d)^c	1.14 (d, 7)		11.9	0.97 (d, 6.5)
OH	1.80 (s) OH	–	–	–		–	–
[α]_D (solvent)	−8 (E)	nd	nd	nd	nd		nd
Source of compound	Euryops floribundus	Synthetic	Synthetic	Synthetic	Synthetic		Synthetic
Ref	31, 32	7	33	9	34		9

Abbreviation: nd, not displayed.

Structure revised from 10βH to 10αH.

H-6 may be ABq; better be revised to 2.90 (d, 16.0) and 2.36 (d, 16.0).

J not shown.

Table 16 includes the data of 3β-hydroxyfuranoeremophilan-9-one (73),^7,9,33 and three 3-acetoxyfuranoeremophilan-9-ones, 74-76 (Figure 8).^34-36 Compounds 74-76 are acetates of euryopsonol (70), 71, and 73, respectively. Compound 75 and 76 are C-10 epimers. Unfortunately, no ¹H NMR data was found for compounds 74 and 75.³⁴ Cis-fused compound 73 can be isomerized to the corresponding trans-fused derivative under basic conditions. The ORD spectrum of compound 73 was measured.⁷

Table 16.

Data of Compounds 73-76.

Compound	73 ^a	73	73	74		75	75		75	76
(solvent)	¹H (C)	¹H (C)	¹H (C)	nd	¹³C (D)	¹H (C)	nd	¹³C (D)	¹H (C)	¹H (C)
1	nd	nd	nd		19.5	nd		15.7	nd	nd
	nd	nd	nd		–	nd		–	nd	nd
2	nd	nd	nd		30.6	nd		29.2	nd	nd
	nd	nd	nd		–	nd		–	nd	nd
3	4.17 (m)	4.56 (m)	4.14 (m)		73.8	5.01 (m)		72.7	5.00 (m)	5.18 (m)
4	nd	nd	nd		46.2	nd		43.6	nd	nd
5	–	–	–		43.5	nd		42.3	–	–
6	nd	2.22 (d, 17)	2.21 (d, 17)		34.6	nd		34.7	2.43 (d, 17)	2.28 (d, 18)
	nd	2.54 (d, 17)	3.02 (d, 17)		–	nd		–	2.70 (d, 17)	3.10 (d, 18)
7	–	–	–		137.3	–		136.5	–	–
8	–	–	–		146.3	–		146.6	–	–
9	–	–	–		185.9	–		185.7	–	–
10	nd	nd	nd		53.9	nd		54.4	nd	nd
11	–	–	–		121.5	–		121.2	–	–
12	7.41 (q, 1.5)	7.38 (q)^b	7.37 (m)		145.2	7.37 (m)		144.6	7.32 (q, 1)	7.36 (q, 1)
13	1.98 (d, 1.5)	1.98 (d)^b	1.98 (d, 1)		7.4	2.00 (d, 1)		7.2	1.99 (d, 1)	1.99 (d, 1)
14	1.10 (s)	1.09 (s)	1.08 (s)		12.8	0.98 (s)		13.3	0.96 (s)	1.07 (s)
15	0.99 (d, 7)	0.97 (d)^b	0.97 (d, 7)		10.5	1.04 (d, 7)		11.2	1.02 (d, 7)	0.96 (d, 7)
1'	–	–	–		170.5	–		169.7	–	–
2'	–	–	–		21.0	2.06 (s)		20.8	2.06 (s)	2.08 (s)
[α]_D (solvent)	−31 (M)	nd	nd	nd		+27 (M)	nd		nd	nd
Source of compound	synthetic	synthetic	synthetic	synthetic		synthetic	synthetic		synthetic	synthetic
Ref	7	33	9	34		35	34		36	36

Abbreviation: nd, not displayed.

ORD measured.

J not shown.

The data of four 3α-acyloxyfuranoeremophilan-9-ones, 77-80,^37-41 and franchetianone B (81)⁴² (Figure 8) are listed in Table 17. Compounds 77-80, have 10αH, while 81 10βH. Because the 3β-H signals of compounds 77-80 have 2 large coupling constants, they should be in the axial position. The shape 'dm' of H-6 of compound 79 in reference 39 better change to br d. The ¹³C NMR data of 19.4 assigned to C-6 of 79 should be corrected to C-1.⁴⁰ The structure of compound 80 was determined by X-ray.⁴¹ The ¹H NMR data of compound 81 was measured at 60 °C.⁴² One of the H-6 protons of compound 81 was not shown in the original reference 42, therefore, it was found from the 2D data of our own experiments.²⁹ The structure of compound being compared with franchetianone B (81) in the original paper (compound 4 in reference 42) was wrong; it should be the 3α-angeloyloxy derivative.³⁷

Table 17.

Data of Compounds 77-81.

Compound	77	78	79	79		80	80 ^d	80	81 ^e
(solvent)	¹H (C)	nd	¹H (C)	nd	¹³C (C)	¹H (C)^c	¹H (C)	nd	¹H (B)
1	nd	2.28 (dddd, 14, 3, 3, 3)	nd		19.4^b	nd	nd	2.55 (dddd, 13, 4, 4, 4)	nd
	nd	1.53 (dddd, 14, 12, 12, 4)	nd		–	nd	nd	1.74 (dddd, 13, 13, 4, 4)	nd
2	nd	1.32 (dddd, 13, 12, 11, 3)	nd		31.1	nd	nd	1.45 (m)	nd
	nd	2.17 (dddd, 13, 4, 4, 3)	nd		–	nd	nd	1.97 (m)	nd
3	4.84 (ddd, 10, 10, 4)	4.74 (ddd, 11, 11, 4)	4.73 (ddd, 10.5, 10.5, 4)		73.7	4.74 (ddd)	4.84 (td, 10.5, 4)	4.91 (ddd, 10, 10, 4.5)	5.22 (dt, 9.5, 4.4)
4	nd	1.78 (dq, 11, 7)	nd		47.1	nd	nd	1.80 (dq, 10, 7)	nd
5	–	–	–		43.9	–	–	–	–
6	2.79 (br d, 16.5)	2.76 (d, 17)	2.74 (dm, 17)^a		35.4	2.38 (d, 16)	2.50 (d, 16.3)	2.44 (d, 17)	2.74 (d, 17.2)
	2.46 (br d, 16.5)	2.50 (br d, 17)	2.42 (dm, 17)^a		–	2.72 (d, 16)	2.77 (d, 16.3)	2.97 (br d, 17)	1.82 (overlapped)^f
7	–	–	–		121.2	–	–	–	–
8	–	–	–		146.6	–	–	–	–
9	–	–	–		186.2	–	–	–	–
10	nd	2.42 (dd, 12, 3)	nd		54.8	nd	nd	2.43 (dd, 4, 4)	2.22 (dd, 10.2, 4.0)
11	–	–	–		136.5	–	–	–	–
12	7.37 (q, 1)	7.38 (q, 1.3)	7.34 (q, 1)		144.6	7.28 (s)	7.37 (d, 1.2)	7.41 (q, 1.2)	6.85 (s)
13	2.00 (d, 1)	2.01 (d, 1.3)	1.97 (d, 1)		7.8	1.99 (d)	2.00 (d, 1.2)	2.00 (d, 1.2)	1.52 (s)
14	0.90 (s)	0.90 (s)	0.82 (s)		13.1	0.89 (s)	0.88 (s)	1.24 (s)	0.84 (s)
15	1.00 (d, 6.5)	1.00 (d, 7)	0.94 (d, 7)		10.5	0.96 (d)	1.00 (d, 6.6)	0.90 (d, 7)	0.75 (d, 7.0)
1'	–	–	–		172.8	–	–	–	–
2'	–	2.38 (tq, 7, 7)	nd		43.8	–	–	–	–
3'	6.07 (dq, 1, 1)	1.6 (m)	nd		25.8	5.95 (qq, 7, 1)	6.00 (qq, 7.4, 1.5)	6.02 (qq, 7, 1)	5.75 (qq, 7.3, 1.4)
	5.62 (dq, 1, 1)	–	–		–	–	–	–
4'	1.96 (t, 1)	0.95 (t, 7)	nd		22.5	1.89 (dq, 7, 1)	1.98 (d, 7.5)	1.82 (dq, 7, 1)	1.97 (dq, 7.3, 1.4)
5'	–	1.19 (d, 7)	nd		22.4	1.98 (dq, 1, 1)	1.91 (d, 1.5)	1.93 (dq, 1, 1)	1.87 (quint, 1.4)
[α]_D (solvent)	nd	−61(C)	−49.5 (C)	nd		nd	nd	nd	nd
Source of compound	Euryops linifolius	S. collinus	Euryops othonnoides	Pittocaulon bombycophole		Euryops hebecarpus	S. aureus	S. oerstedianus	L. franchetiana
Ref	37	38	39	40		37	41	38	42

Abbreviation: nd, not displayed.

Probably (br d).

Original 19.4 (C-6) is wrong, but should be C-1.

J not shown.

X-ray.

Measured at 60°C.

The data of H-6β not in the ref, taken from 2D data.

Table 18 compiles the data of four 3-acyloxyfuranoeremophilan-9-ones, 82-85^39,40,43,44 and 2 compounds bearing long-chain acyloxy groups, 86 and 87 (Figure 8).⁴⁵ All compounds have 10αH. Compounds 83-87 have 3α-acyloxy groups, while 82 a 3β-acyloxy group. The structure of compound 83 was solved by X-ray to show C-3' (S).⁴⁰ The original ¹³C NMR data of C-7 and 8 of compound 83 should be interchanged as shown in Table 18.⁴⁰

Table 18.

Data of Compounds 82-87.

Compound	82	83 ^a		84	85		86	87
(solvent)	¹H (C)	¹H (C)	¹³C (C)	¹H (C)	¹H (B)	¹³C (B)	¹H (C)	¹H (C)
1	2.28 (dddd, 12, 3.5, 3, 3)	2.24 (m)	19.3	nd	2.28-2.32 (m)	19.8	nd	nd
	1.53 (dddd, 12, 12, 12, 3.5)	1.55 (m)	–	nd	1.37-1.44 (m)	–	nd	nd
2	1.33 (dddd, 12, 12, 11, 3)	2.20 (m)	31.1	nd	1.05-1.13 (m)	31.4	nd	nd
	2.19 (dddd, 12, 11, 3.5, 3)	1.32 (m)	–	nd	2.05-2.10 (m)	–	nd	nd
3	4.75 (ddd, 11, 11, 4.5)	4.74 (ddd, 10.8, 10.8, 4.5)	73.7	4.94 (ddd, 10.5, 10.5, 4)	4.76 (td, 11.3, 4.6)	59.8	4.83 (ddd, 11, 11, 4.5)	4.83 (ddd, 11, 11, 4.5)
4	1.74 (dq, 11, 7)	1.76 (dq, 10.8, 6.6)	47.1	nd	1.37-1.41 (m)	47.0	nd	nd
5	–	–	43.9	–	–	43.4	–	–
6	2.74 (d, 16.5)	2.72 (d, 16.2)	35.4	2.80 (d, 17)	1.82 (d, 16.1)	35.2	2.77 (d, 16.5)	2.40 (d, 16.5)
	2.47 (d, 16.5)	2.50 (d, 16.2)	–	2.47 (d, 17)	2.25 (d, 16.1)	–	2.50 (d, 16.5)	2.15 (d, 16.5)
7	–	–	136.5^b	–	–	135.2	–	–
8	–	–	146.6^b	–	–	150.0	–	–
9	–	–	186.1	–	–	185.5	—	4.28 (m)
10	2.41 (dd, 12, 3.5)	2.41 (dd, 12.0, 3.6)	54.8	nd	1.79-1.81 (m)	54.7	2.44 (dd, 10, 3)	nd
11	–	–	121.2	–	–	120.8	–	–
12	7.36 (br s)	7.36 (q, 1.2)	144.6	7.34 (q, 1)	6.77 (q, 1.0)	144.1	7.38 (q, 1)	7.14 (br s)
13	1.98 (br s)	1.99 (d, 1.2)	7.7	1.98 (d, 1)	1.48 (d, 1.0)	7.4	2.00 (d, 1)	1.92 (br s)
14	0.84 (s)	0.86 (s)	13.1	0.90 (s)	0.47 (s)	12.7	0.88 (s)	0.80 (s)
15	0.94 (d, 7)	0.97 (d, 6.6)	10.5	1.02 (d, 7)	0.73 (d, 6.8)	10.6	0.98 (d, 6.5)	0.94 (d, 6.5)
1'	–	–	172.9	–	–	169.2	–	–
2'	5.68 (br s)	2.30 (dd, 14.4, 6.0)	41.8	–	–	59.3	5.89 (d, 15)	5.86 (d, 15)
	–	2.12 (dd, 14.4, 8.1)	–	–	–	–	–	–
3'	–	1.90 (oct, 6.6)	32.0	nd	2.60 (q, 5.4)	59.8	7.69 (dd,15, 12)	7.68 (dd, 15, 12)
4'	2.17 (br s)	1.39 (m)	29.4	nd	1.18 (d, 5.4)	14.1	6.11 (d, 12)	6.10 (d, 12)
	–	1.27 (m)	–	–	–	–	–	–
5'	1.89 (br s)	0.91 (t, 7.5)	11.2	–	–	–	—	—
6'	–	0.95 (d, 6.6)	19.2	nd	1.42 (s)	19.5	6.16 (d, 15)	6.16 (d, 15)
7'	–	–	–	–	–	–	5.96 (dt, 15, 7)	5.95 (dt, 15, 7)
8'	–	–	–	–	–	–	2.17 (dt, 7, 7) 2H	2.16 (dt, 7, 7) 2H
9'	–	–	–	–	–	–	1.43 (tt, 7, 7) 2H	1.43 (tt, 7, 7) 2H
10'	–	–	–	–	–	–	1.31 (m) 2H	1.31 (m) 2H
11'	–	–	–	–	–	–	1.31 (m) 2H	1.31 (m) 2H
12'	–	–	–	–	–	–	0.92 (t, 6.5)	0.90 (t,6.5)
13'	–	–	–	–	–	–	1.99 (br s)	1.99 (br s)
[α]_D (solvent)	−61.8 (C)	−32 (C)		−87 (C)	−42.0 (E)		nd	nd
Source of compound	S. smithii	Pittocaulon bombycophole		Euryops othonnoides	Cr. lineare		S. speciosus	S. speciosus
Ref	43	40		39	44		45	45

Abbreviation: nd, not displayed.

The structure determined by X-ray (C3' S).

Original data interchanged.

Table 19 presents the data of 3 furanoeremophilane-3,9-diones, 88-90,^7,9,33,34 and 6β-acyloxy-9-hydroxyfuranoeremophilan-3-one, 91 (Figure 9).²⁹ Dehydroeuryopsonol (89) has 10αH, while compounds 88, 90, and 91 10βH. Compound 88 has a C-4α substituted methyl group, and compounds 88 and 90 are C-4 epimers. Unfortunately, no H-4 was recorded for compounds 88-90. Compound 91, which adopts a non-steroid-like conformation (vide infra), have been isolated from Ligularia stenoglossa, the data being reported in the meeting, but the data not published in the literature.²⁹

Figure 9.

Compounds 88-104.

Table 19.

Data of Compounds 88-91.

Compound	88	89	89	89		90	90	91
(solvent)	¹H (C)	¹H (C)	¹H (C)	nd	¹³C (D)	¹H (C)	¹H (C)	¹H (B)	¹³C (B)
1	nd	nd	nd		21.8	nd	nd	1.96 (m)	22.0
	nd	nd	nd		–	nd	nd	1.62 (m)	–
2	nd	nd	nd		39.4	nd	nd	2.15 (td, 14.9, 5.2)	36.6
	nd	nd	nd		–	nd	nd	1.87 (dt, 14.9, 7.6)	–
3	–	–	–		210.5	–	–	–	208.7
4	nd	nd	nd		53.3^a	nd	nd	1.67 (q, 6.6)	47.3
5	–	–	–		46.1	–	–	–	46.2
6	nd	nd	nd		33.7	nd	nd	5.97 (s)	68.0
7	–	–	–		137.4	–	–	–	118.6
8	–	–	–		146.0	–	–	–	153.7
9	–	–	–		184.9	–	–	4.41 (dd, 8.4, 6.5)	63.9
10	nd	2.94 (dd, 12, 3.5)	2.94 (dd, 11, 3.5)		52.7^a	nd	nd	2.12 (m)	44.5
11	–	–	–		121.7	–	–	–	119.7
12	7.40 (m)	7.39 (q)	7.39 (m)		145.5	7.42 (q, 1.5)	7.42 (m)	6.88 (s)	140.1
13	1.96 (d, 1)	2.00 (d)	2.00 (d, 1)		7.2	2.01 (d, 1.5)	2.00 (d, 1)	1.97 (s)	8.2
14	1.20 (s)	0.75 (s)	0.77 (s)		13.4	1.11 (s)	1.09 (s)	0.78 (s)	18.6
15	1.09 (d, 7)	1.07 (d)	1.07 (d, 6)		7.2	0.96 (d, 7)	0.96 (d, 7)	0.91 (d, 6.6)	8.1
1'	–	–	–		–	–	–	–	172.0
2'	–	–	–		–	–	–	1.93 (d, 6.8)	43.3
	–	–	–		–	–	–	1.93 (d, 6.8)	–
3'	–	–	–		–	–	–	2.04 (tsept, 6.8)	25.7
4'	–	–	–		–	–	–	0.78 (d, 6.8)	22.3
5'	–	–	–		–	–	–	0.78 (d, 6.8)	22.4
OH	–	–	–		–	–	–	1.45 (d, 6.5)	–
[α]_D (solvent)	nd	nd	nd	nd		+26 (M)	nd	−62.5 (E)
Source of compound	Synthetic	Synthetic	Synthetic	Synthetic		Synthetic	Synthetic	L. stenoglossa
Ref	9	33	9	34		7	9	29

Abbreviation: nd, not displayed.

May be interchanged.

The data of three dihydroxyfuranoeremophilan-6-one monoacetates, 92-94,³³ dihydroxyfuranoeremophilan-9-one monomethylether, 95,^14,27 and three dihydroxyfuranoeremophilan-9-one monoacetates, 96-98³¹ (Figure 9) are provided in Table 20. Compounds 92, 93, 95, and 96 have 10αH, while 94, 97, and 98 10βH. Compounds 92 and 93 have C-4α methyl group, and compounds 92 and 93 are C-3 epimers. Compounds 96 and 97 are C-10 epimers, and 97 and 98 C-3 epimers. Detailed J values were not shown in reference 33.

Table 20.

Data of Compounds 92-98.

Compound	92	93	94	95	95	96	97	98
(solvent)	¹H (C)^a	¹H (C)	¹H (C)^a	¹H (C)	¹H (C)	¹H (C)^a	¹H (C)^a	¹H (C)^a
1	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd
2	nd	nd	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd	nd	nd
3	4.07 (ddd, 10, 6, 5)	3.95 (m)	4.73 (ddd, 11, 4.5, 4.5)	3.93 (ddd, 4, 3, 2.5)	3.98 (ddd, 3, 3, 3)	4.75 (ddd, 10.5, 10.5, 5)	4.74 (ddd 10.5, 10.5, 5.5)	5.8 (m)
4	nd	nd	nd	2.31 (qd, 7, 3)	2.32 (qd, 7, 3)	nd	nd	nd
6	–	–	–	4.02 (s)	4.03 (s)	4.57 (s)	5.02 (s)	4.63 (s)
9	5.86 (d, 10)	5.93 (d, 10)	5.22 (d, 6)	–	–	–	–	–
10	nd	nd	nd	2.88 (br d, 11)	2.88 (dd, 12, 3)	3.28 (dd, 12, 4)	nd	nd
12	7.15 (br s)	7.15 (br s)	7.17 (br s)	7.37 (q, 1)	nd	7.38 (q)	7.39 (q)	7.32 (q)
13	2.19 (s)	2.19 (s)	2.20 (d)	2.12 (d, 1)	nd	2.10 (d)	2.19 (d)	2.07 (d)
14	1.20 (s)	1.44 (s)	1.14 (s)	0.90 (s)	0.90 (s)	0.78 (s)	1.31 (s)	1.01 (s)
15	0.92 (d)^a	0.91 (d)^a	1.00 (d)	1.08 (d, 7)	1.08 (d, 7)	0.98 (d)	1.01 (d)	0.99 (d)
OAc/OMe	2.18 (s)	2.18 (s)	–	nd	nd	2.06 (s)	1.97 (s)	nd
[α]_D (solvent)	nd	nd	nd	0 (C)	nd	nd	nd	nd
Source of compound	Synthetic	Synthetic	Synthetic	Synthetic	nd	Synthetic	Synthetic	Synthetic
Ref	33	33	33	14	27	33	33	33

Abbreviation: nd, not displayed.

J not shown.

Measured at 70°C.

Measured at 75°C.

The data of two 6β-acyloxy-3β-hydroxy-9-ones, 99 and 100,^23,46 and three 3-acyloxy-1α-hydroxyfuranoeremophilan-9-ones, 101-103 (Figure 9)⁴³ are tabulated in Table 21. Compounds 99 and 100 have 10βH, while 101-103 10αH. Compounds 101-103 have C-1α hydroxy groups. The ¹H NMR data of compounds 99⁴⁶ and 100²³ were measured at 70 and 75 °C, respectively. The specific rotations of compounds 102 and 103 were measured at 365 nm, because those at D-lines were too small.

Table 21.

Data of Compounds 99-103.

Compound	99	99	100	101	102 ^d	103 ^e
(solvent)	¹H (C)	¹H (D)^a	¹H (B)^b,c	¹H (C)	¹H (C)	¹H (C)
1	nd	1.48 (m)	nd	–	–	–
	nd	1.48 (m)	nd	4.24 (br ddd, 11.5, 11, 5)	4.26 (br ddd, 11.5, 11, 5)	4.24 (br ddd, 11.5, 11, 5)
2	nd	1.28 (m)	nd	1.45 (ddd, 12, 11.5, 11)	1.51 (ddd, 12, 11.5, 11)	1.48 (ddd, 12, 11.5, 11)
	nd	1.28 (m)	nd	2.40 (ddd, 12, 5, 5)	2.47 (ddd, 12, 5, 5)	2.43 (ddd, 12, 5, 5)
3	4.2 (br)	3.72 (br)	3.63 (m)	4.80 (ddd, 11, 11, 5)	4.92 (ddd, 11, 11, 5)	4.87 (ddd, 11, 11, 5)
4	nd	1.39 (m)	2.00 (m)	1.81 (dq, 11, 7)	1.86 (dq, 11, 7)	1.89 (dq, 11, 7)
6	6.61 (br)	6.27 (br)	6.39 (br s)	2.71 (d, 17)	2.73 (d, 17)	2.71 (d, 17)
	–	–	–	2.52 (d, 17)	2.53 (d, 17)	2.52 (d, 17)
10	2.50-2.70 (m)	2.26 (m)	2.62 (dd, 7, 4)	2.42 (d, 11)	2.44 (d, 11)	2.42 (d, 11)
12	7.04 (br s)	7.59 (br s)	6.84 (br s)	7.42 (br s)	7.43 (br s)	7.42 (br s)
13	1.96 (br s)	1.70 (d, 0.3)	1.82 (br s)	2.01 (br s)	2.01 (br s)	2.00 (br s)
14	1.24 (s)	0.86 (s)	1.21 (s)	0.86 (s)	0.89 (s)	0.87 (s)
15	0.96 (d, 6.9)	0.67 (d, 7.2)	0.81 (d, 7)	0.95 (d, 7)	0.98 (d, 7)	0.96 (d, 7)
2'	2.63 (m)	2.49 (hept, 6.9)	2.26 (tq)	2.56 (qq, 7, 7)	–	5.69 (br s)
3'	1.22 (d, 7.0)	0.99 (d, 7.5)	nd	1.18 (d, 7)	6.07 (qq, 7, 1.5)	–
4'	1.22 (d, 7.0)	0.95 (d, 7.2)	0.80 (t)	1.17 (d, 7)	1.98 (dq, 7, 1.5)	2.18 (br s)
5'	–	–	1.05 (d)	–	1.91 (dq, 1.5, 1.5)	1.91 (br s)
[α]_D (solvent)	−38 (C)	−38 (C)	nd	nd	−0.8 (C)	0 (C)
Source of compound	Synthetic	Synthetic	Synthetic	S. smithii	S. smithii	S. smithii
Ref	46	46	23	43	43	43

Abbreviation: nd, not displayed.

Measured at 70°C.

Measured at 75°C.

J not shown.

[α]₃₆₅ −149.1 (C)

[α]₃₆₅ −123.7 (C)

Table 22 gives the data of 3α-acyloxy-13-hydroxyfuranoeremophilan-9-one, 104 (Figure 9),³⁹ and three 3β-acetoxy-6β-acyloxyfuranoeremophilan-9-ones, 105-107 (Figure 10).^23,46-48 The ¹H NMR of compound 107 was measured at 75 °C and 72 °C in references 23 and 48, respectively. Sendarwin I (105) and 104 have 10αH, while 106 and 107 10βH. Sendarwin I (105) and 106 are C-10 epimers.

Figure 10.

Compounds 105-119.

Table 22.

Data of Compounds 104-107.

Compound	104	105		106	107	107
(solvent)	¹H (C)	¹H (C)^a	¹³C (C)	¹H (C)	¹H (B)^b	¹H (B)^c
1	nd	2.06	15.7	1.6-2.0 (m)	nd	nd
	nd	2.66	–	1.6-2.0 (m)	nd	nd
2	nd	1.95	29.5	1.6-2.0 (m)	nd	nd
	nd	2.49	–	1.6-2.0 (m)	nd	nd
3	4.71 (ddd, 10.5, 10.5, 4)	4.88	75.0	5.09 (br)	5.00 (ddd, 9, 4, 4)	4.96 (m)
4	nd	1.95	44.1	1.6-2.0 (m)	1.97 (m)	nd
5	–	–	49.5	–	–	–
6	2.90 (d, 17)	6.29	75.8	6.4 (br)	6.37 (br s)	6.32 (s)
7	2.53 (d, 17)	–	134.3	–	–	–
8	–	–	146.8	–	–	–
9	–	–	185.2	–	–	–
10	nd	2.41	54.9	2.6-2.8 (m)	2.63 (dd, 7, 4)	2.62 (m)
11	-	–	120.9	–	–	–
12	7.53 (q, 1)	7.31	145.2	7.41 (q, 1.2)	6.85 (br s)	6.80 (q, 1)
13	nd	1.83	8.8	1.99 (br s)	1.81 (br s)	1.81 (d, 1)
14	0.83 (s)	1.08	9.8	1.22 (m)	1.16 (s)	1.15 (s)
15	0.94 (d, 7)	0.92	14.6	0.93 (d, 6.9)	0.76 (d, 7)	0.76 (d, 7)
1'	–	–	176.4	–	–	–
2'	nd	2.62	34.5	2.6-2.8 (m)	2.26 (tq)^d	nd
3'	nd	1.21	18.6	1.22 (m)	nd	nd
4'	nd	1.21	18.7	1.22 (m)	0.78 (t)^d	nd
5'	nd	–	–	–	1.08(d)^d	nd
1''	nd	–	170.4	–	–	–
2''	–	2.02 (s)	21.2	2.06 (s)	1.68 (s)	1.67 (s)
[α]_D (solvent)	nd	−157.3 (C)		−59 (C)	nd	nd
Source of compound	Euryops othonnoides	S. darwinii		Synthetic	S. medley-woodii	Synthetic
Ref	39	47		46	23	48

Abbreviation: nd, not displayed.

Shape and J not shown.

Measured at 75 °C.

Measured at 72 °C.

J not shown.

The data of four 3,6-diacyloxyfuranoeremophilan-9-ones, 108-111,^46,49-51 and methyl ester 112 (Figure 10)¹⁴ are found in Table 23. Compounds 108, 111, and 112 have 10αH, while 109 and 119 10βH. Compounds 108 and 109 are C-10 epimers. Compounds 109 and 110 have an angeloyloxy and a tigloyloxy group, respectively. The acyl group of compound 111 is 2,3-epoxy-2-methylbutanoyl, but the configurations have not been determined. The ¹H NMR of compound 109 was measured at 60 °C.⁴⁹

Table 23.

Data of Compounds 108-112.

Compound	108		109	110	111	112
(solvent)	¹H (C)	¹³C (C)	¹H (B)^a	¹H (B)	¹H (C)	¹H (C)
1	2.10 (m)	15.7	nd	nd	nd	nd
	1.72 (br dtd, 14.0, 12.3, 3.6)	–	nd	nd	nd	nd
2	1.53 (br tt, 14.1, 3.3)	29.5	nd	nd	nd	nd
	2.10 (m)	–	nd	nd	nd	nd
3	4.94 (dd, 5.4, 3.3)	75.4	5.12 (m)	5.15 (m)	4.96 (ddd, 5)^b	5.05 (m)
4	2.00 (m)	44.1	nd	nd	2.00 (m)	nd
5	–	49.5	–	–	–	–
6	6.43 (s)	75.9	6.56 (s)	6.59 (br s)	6.35 (s)	3.97 (s)
7	–	146.8	–	–	–	–
8	–	121.0	–	–	–	–
9	–	185.7	–	–	–	–
10	2.47 (dd, 11.4, 3.2)	55.0	2.62 (dd, 7, 4)	2.63 (dd, 8, 4.5)	2.45 (dd)^b	2.83 (dd, 10, 3)
11	–	134.7	–	–	–	–
12	7.13 (q, 1.3)	145.1	6.89 (q, 1)	6.86 (br s)	7.40 (q, 1.3)	7.33 (q, 1)
13	1.79 (d, 1.3)	8.5	1.80 (d, 1)	1.67 (br s)	1.95 (d, 1.3)	2.14 (d, 1)
14	1.27 (s)	10.0	1.15 (s)	1.15 (s)	1.17 (s)	0.85 (s)
15	0.91 (d, 7.0)	14.2	0.79 (d, 7)	0.78 (d, 7)	0.98 (d, 7)	0.95 (d, 7)
1'	–	167.2	–	–	–	–
2'	–	127.0	–	–	–	–
3'	6.30 (qq, 7.2, 1.5)	141.8	5.80 (qq, 7, 1.5)	6.85 (qq, 7, 1.5)	3.17 (q)^b	5.98 (br s)
	–	–	–	–	–	5.45 (br s)
4'	2.10 (m)	16.0	1.93 (dq, 7, 1.5)	1.41 (dq, 7, 1.5)	1.48 (d)^b	1.80 (br s)
5'	1.97 (m)	20.3	1.69 (dq, 1.5, 1.5)	1.77 (dq, 1.5, 1.5)	1.62 (s)	–
1''	–	170.4	–	–	–	–
2''	2.07 (s)	21.2	1.82 (s)	1.81 (s)	2.08 (s)	3.37 (s) OMe
[α]_D (solvent)	−33 (C)		nd	nd	−10.2 (C)	nd
Source of compound	Synthetic		Gynoxys psilophylla	S. pyramidatus	Euryops oligoglossus	Synthetic
Ref	46		49	50	51	14

Abbreviation: nd, not displayed.

Measured at 60 °C.

J not shown.

Table 24 lists the data of two 3,6-diacyloxyfuranoeremophilan-9-ones, 113 and 114,^40,52 and two 3β-senecioyloxy-6-methoxyfuranoeremophilan-9-ones, 115 and 116,^14,27 (Figure 10). Compounds 115 and 116 are C-6 epimers. Compound 113 has 10βH, while 114-116 10αH. The data of compound 115 is due to a mixture with a 3-angeloyloxy derivative.²⁷

Table 24.

Data of Compounds 113-116.

Compound	113	114		115 ^a	116
(solvent)	¹H (C)	¹H (C)	¹³C (C)	¹H (C)	¹H (C)
1	2.18 (m)	2.31 (dddd, 12.5, 12.0, 7.0, 3.5)	19.0	nd	nd
	1.85 (m)	1.62 (m)	–	nd	nd
2	1.72 (m)	2.23 (dddd, 12.5, 8.0, 4.0, 3.5)	30.8	nd	nd
	1.72 (m)	1.36 (m)	–	nd	nd
3	5.17 (br q, 3.5)	4.71 (ddd, 10.8, 10.8, 4.5)	73.6	5.19 (ddd, 3, 3, 3)	5.05 (m)
4	1.90 (m)	2.02 (m)	46.1	2.56 (dq, 3, 3)	nd
5	–	–	50.1	–	–
6	6.33 (br s)	6.40 (s)	75.3	4.04 (s)	3.97 (s)
7	–	–	134.7	–	–
8	–	–	146.5	–	–
9	–	–	185.2	–	–
10	2.75 (br dd, 6, 4)	2.47 (dd, 12.0, 3.5)	54.4	2.94 (dd)^b	2.83 (dd, 10, 3)
11	–	–	120.9	–	–
12	nd	7.37 (q, 1.2)	145.4	nd	7.33 (q, 1)
13	2.03 (d, 1)	1.92 (d, 1)	8.5	nd	2.14 (d, 1)
14	1.27 (s)	1.02 (s)	8.9	0.87 (s)	0.85 (s)
15	0.98 (d, 7)	0.94 (d, 6.6)	12.1	0.98 (d, 7)	0.95 (d, 7)
1'	–	–	167.6	–	–
2'	2.43 (tq, 7, 7)	–	127.9	nd	5.55 (qq, 1, 1)
3'	1.85 (m)	6.06 (qq, 7.2, 1.5)	137.8	–	–
	1.48 (ddq, 14, 7, 7)	–	–	–	–
4'	0.89 (t, 7)	1.98 (dq, 7.2, 1.5)	20.5	nd	2.17 (d, 1)
5'	1.19 (d, 7)	1.88 (quint, 1.5)	15.7	nd	1.88 (d, 1)
1''	–	–	170.8	nd	3.37 (s)
2''	–	2.19 (s)	21.5	–	–
3''	6.02 (qq, 7, 1.5)	–	–	–	–
4''	1.98 (dq, 7, 1.5)	–	–	–	–
5''	1.92 (dq, 1.5, 1.5)	–	–	–	–
[α]_D (solvent)	nd	−117 (C)		+114.0 (C)	nd
Source of compound	Hertia pallens	Pittocaulon bombycophole		nd	Synthetic
Ref	52	40		27	14

Abbreviation: nd, not displayed.

Mixture with a 3β-angeloyloxy derivative.

J not shown.

Table 25 compiles the data of two 3,6-diacyloxyfuranoeremophilan-9-ones, 117 and 118,^27,40 and 3,10-diacyloxyfuranoeremophilan-9-one, 119 (Figure 10).⁵³ The absolute configurations of C-3' of compound 118, and C-10 of compound 119 were not determined. Compound 117 is a mixture with 2 similar compounds; 3-angeloyloxy-6-senecioyloxy- and 3-tigloyloxy-6-angeloyloxyfuranoeremophilan-9-one.²⁷ The H-2' data of compound 118 must be (dd, 14.0, 6.5) for both protons.⁴⁰ The original ¹³C NMR data of C-7 and 8 of compound 118 should be interchanged as shown in Table 27.²⁵ In the case of compounds having an oxo group at C-9, chemical shifts of C-7 appear at δ 135-140. This is a marked difference from those without C-9 oxo groups, chemical shifts of which are about δ 115-120.

Table 25.

Data of Compounds 117-119.

Compound	117 ^a	118		119
(solvent)	¹H (C)	¹H (C)	¹³C (C)	¹H (C)
1	nd	2.27 (m)	18.9	nd
	nd	1.60 (m)	–	nd
2	nd	2.16 (m)	30.6	nd
	nd	1.31 (m)	–	nd
3	5.23 (m)	4.61 (ddd, 11.0, 11.0, 5.0)	73.7	5.20 (m)
4	nd	1.94 (m)	45.9	nd
5	–	–	50.0	–
6	6.59 (br s)	6.39 (s)	75.3	nd
7	–	–	134.7^c	–
8	–	–	146.5^c	–
9	–	–	185.2	–
10	2.65 (m)	2.44 (dd, 12.5, 3.5)	54.3	–
11	–	–	120.8	–
12	nd	7.36 (q, 1.0)	145.4	7.39 (q, 1)
13	nd	1.92 (d, 1.0)	8.5	1.98 (d, 1)
14	0.82 (br s)	0.99 (s)	9.0	1.25 (s)
15	0.82 (br s)	0.91 (d, 6.7)	12.0	0.97 (d)^d
1'	–	–	172.9	–
2'	nd	2.29 (ddd, 14.0, 14.0, 6.5)^b	41.8	–
	–	2.10 (ddd, 14.0, 14.0, 6.5)^b	–	–
3'	–	1.88 (m)	32.0	–
4'	nd	1.36 (m)	29.4	–
	–	1.26 (m)	–	–
5'	nd	0.90 (t, 7.2)	11.2	–
6'	–	0.93 (d, 6.5)	19.2	–
OAc	–	2.19 (s)	–	–
[α]_D (solvent)	nd	−98 (M)		nd
Source of compound	Othonna triplenerva	Pittocaulon bombycophole		Othonna quinquedentata
Ref	27	40		53

Abbreviation: nd, not displayed.

Mixture with 3-angeloyloxy-6-senecioyloxy and 3-tigloyloxy-6-angeloyloxy derivatives.

Both must be (dd, 14.0, 6.5).

Original assignment reversed.

J not shown.

Table 26 presents the data of 6α-hydroxyfuranoeremophilane-3,9-dione, 120,⁹ three 9-hydroxyfuranoeremophilane-3,6-diones, 121-123,^9,33 and two 3-hydroxyfuranoeremophilane-6,9-diones, 124 and 125 (Figure 11).³³ Compounds 120-123 are 3-ones. Compounds 121 and 122 have 10αH, while compound 120 and 123-125 10βH. Unfortunately, no J values were shown for some data.

Figure 11.

Compounds 120-135.

Table 26.

Data of Compounds 120-125.

Compound	120	121	122	123	124	125
(solvent)	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹H (C)^a	¹H (C)^a
1	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd
2	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd
3	–	–	–	–	nd	3.77 (m)
4	nd	nd	nd	3.25 (q, 7)	nd	nd
6	4.66 (br s)	–	–	–	–	–
9	–	4.71 (d, 10)	4.95 (d, 4)	5.25 (t, 5)	–	–
10	nd	nd	nd	nd	nd	nd
12	7.43 (m)	7.21 (q, 1)	7.21 (q, 1)	7.20 (m)	7.47 (q)^a	7.47 (q)^a
13	2.09 (d, 1)	2.23 (d, 1)	2.25 (d, 1)	2.18 (d, 1)	2.19 (d)^a	2.19 (d)^a
14	1.01 (s)	1.08 (s)	1.29 (s)	1.17 (s)	1.28 (s)	1.30 (s)
15	1.01 (d, 7)	1.19 (d)^a	1.13 (d)^a	1.04 (d, 7)	0.94 (d)^a	0.98 (d)^a
OH	3.28 (s)	–	–	–	–	–
[α]_D (solvent)	nd	nd	nd	nd	nd	nd
Source of compound	synthetic	synthetic	synthetic	synthetic	synthetic	synthetic
Ref	9	33	33	9	33	33

Abbreviation: nd, not displayed.

J not shown.

The data of four 3-acetoxyfuranoeremophilane-6,9-diones, 126-129,^33,36 and two furanoeremophilane-36,9-triones, 130 and 131 (Figure 11),³³ are provided in Table 27. Compounds 126 and 127 are C-3 epimers. Compounds 128 and 129 are enol-acetates, and are C-10 epimers. Compounds 130 and 131 are both triones having different configurations at C-4 and 10. The chemical shift values of H-10 of compounds 130 and 131 are quite different; in compound 130 appearing in the slightly lower field than that of 131. This phenomenon was also seen for compounds 128 and 129.

Table 27.

Data of Compounds 126-131.

Compound	126	127	128	129	130	131
(solvent)	¹H (C)^a	¹H (C)	¹H (C)	¹H (C)	¹H (C)	¹H (C)
1	nd	nd	nd	nd	2.0 (m)	2.07 (dddd, 14, 12, 6.5, 5)
	nd	nd	nd	nd	2.6 (m)	2.93 (dddd, 14, 5.5, 3.5, 3.0)
2	nd	nd	5.37 (dd, 4.5, 3.5)	5.35 (dd, 5, 2.5)	2.4 (m)	2.5 (m)
	nd	nd	–	–	2.4 (m)	2.5 (m)
3	nd	4.81 (m)	–	–	–	–
4	nd	nd	nd	nd	2.91 (qd, 7, 1)	2.70 (q, 7)
5	–	–	–	–	–	–
6	–	–	–	–	–	–
7	–	–	–	–	–	–
8	–	–	–	–	–	–
9	–	–	–	–	–	–
10	2.80 (dd, 4.5, 4)	nd	3.22 (dd, 10.5, 6)	2.99 (dd, 7, 1.5)	3.52 (dd, 12, 3.5)	3.05 (dd, 5, 3)
11	–	–	–	–	–	–
12	7.47 (q)	7.44 (q, 1)	7.46 (q, 1)	7.43 (q, 1)	7.50 (q, 1.1)	7.53 (q, 1.1)
13	2.27 (d)	2.27 (d, 1)	2.30 (d, 1)	2.30 (d, 1)	2.29 (d, 1.1)	2.29 (d, 1.1)
14	1.30 (s)	1.03 (s)	1.36 (s)	1.61 (s)	1.17 (m)	1.22 (s)
15	0.83 (d)	0.95 (d)	1.15 (d, 7)	0.73 (d, 7)	1.25 (d, 7)	0.85 (d, 7)
OAc	nd	2.07 (s)	2.16 (s)	2.10 (s)	–	–
[α]_D (solvent)	nd	nd	nd	nd	nd	nd
Source of compound	synthetic	synthetic	synthetic	synthetic	synthetic	synthetic
Ref	33	36	33	33	33	33

Abbreviation: nd, not displayed.

J not shown.

Table 28 tabulates the data of three diacyloxyeremophilanols, 132-134,^46,54,55 and 3β-angeloyloxy-9β-methoxyfuranoeremophilan-6β-ol, 135 (Figure 11).⁵⁶ The configuration of C-6 of kablicin (132) was not determined. Roldehrenbergins A and B, 134 and 133, have 10α-H, while kablicin (132) and 135 10β-H. Roldehrenbergin A (134) has an angeloyloxy group at C-6β, while roldehrenbergin B (133) a 2-methylpropanoyloxy group. Only a part of data were reported for kablicin (132)^54,55 The original data of ¹³C NMR chemical shifts of C-7 and 8 of both compounds 133 and 134 were interchanged, as discussed before.

Table 28.

Data of Compounds 132-135.

Compound	132	133		134		135
(solvent)	¹H (C)	¹H (C)	¹³C (C)	¹H (C)	¹³C (C)	¹H (C)	¹³C (C)	¹H (B)	¹³C (B)
1	nd	1.49 (dddd, 14.0, 4.5, 3.0, 1.5)	21.0	1.50 (dddd, 14.0, 4.5, 3.0, 1.5)	20.8	1.23 (m)	25.4	nd	25.7
	nd	2.17 (dtd, 14.0, 14.0, 4.0)	–	2.17 (dtd, 14.0, 14.0, 3.5)	–	1.60 (m)	–	nd
2	nd	1.64 (dddd, 14.0, 14.0, 4.4, 3.0)	30.5	1.64 (dddd, 14.0, 14.0, 4.5, 3.0)	30.5	1.82 (m)	25.4	nd	25.7
	nd	2.00 (br dtd, 14.0, 4.0, 3.0)	–	2.11 (br dtd, 14.0, 4.0, 3.0)	–	1.73 (m)	–	nd
3	nd	4.92 (dt, 5.5, 2.5)	75.9	4.92 (dt, 5.5, 2.5)	75.9	5.28 (dt, 11.3, 4.1)	71.7	nd	72.1
4	nd	1.75 (m)	44.8	1.78 (m)	44.7	2.30 (m)	36.2	–	36.6
5	–	–	42.3		42.2	–	42.3	nd	42.8
6	nd	5.93 (d, 1.0)	76.5	6.01 (d, 1.0)	76.2	5.00 (br s)	67.9	5.05 (br s)	67.8
7	–	–	119.5^a	–	119.5^a	–	120.8	–	121.4
8	–	–	151.1^a	–	150.9^a	–	148.9	–	149.5
9	nd	4.53 (d, 4.0)	65.3	4.56 (br s)	65.3	3.90 (br s)	76.0	3.78 (br s)	76.5
10	nd	1.73 (m)	46.8	1.76 (br dt, 14.0, 3.0)	46.6	2.21 (ddd, 12.9, 4.1, 1.9)	41.5	nd	42.4
11	–	–	118.8	–	118.9	–	120.2	nd	120.8
12	7.14 (s)	7.13 (q, 1.0)	140.2	7.36 (q, 1.2)	140.1	7.16 (q, 1.0)	140.4	7.01 (br s)	140.3
13	1.84 (s)	1.81 (d, 1.0)	9.2	1.85 (s)	8.9	2.10 (d, 1.1)	9.0	2.10 (s)	9.2
14	1.10 (s)	1.26 (s)	11.5	1.13 (s)	11.6	1.08 (s)	20.2	1.29 (s)	20.8
15	0.90 (d, 7)	0.91 (d, 6.5)	14.0	0.96 (d, 7.2)	13.7	1.00 (d, 7.1)	8.5	0.96 (d, 6.6)	8.6
1'	–	–	170.6	–	170.6	–	167.5	–	167.2
2'	nd	2.08 (s)	21.3	2.07 (s)	21.3	–	128.1	–	127.8
3'	–	–	–	–	–	6.07 (qq, 7.1, 1.4)	137.8	5.76 (qq, 7.1, 1.4)	138.0
4'	nd	–	–	–	–	2.00 (dq, 7.1, 1.4)	15.7	2.00 (dq, 7.1, 1.4)	15.9
5'	nd	–	–	–	–	1.91 (quint, 1.4)	20.7	1.89 (br s)	20.8
1''	–	–	176.7	–	167.7	3.48 (s)	57.5	3.43 (s)	57.5
2''	–	2.62 (hept, 7.0)	34.7	–	127.7	–	–	–	–
3''	nd	1.23 (d, 7.0)	18.8	6.20 (qq, 7.5, 1.5)	140.3	–	–	–	–
4''	nd	1.24 (d, 7.0)	18.6	2.07 (dq, 7.5, 1.5)	15.9	–	–	–	–
5''	nd	–	–	1.94 (dq, 1.5, 1.5)	20.5	–	–	–	–
[α]_D (solvent)	−18.4 (nd)	+21.7 (M)		+25 (M)		−1.9 (C)
Source of compound	P. kablikiamus, P. paradoxus	Roldana ehrenbergiana		Roldana ehrenbergiana		F. japonicum
Ref	54, 55	46		46		56		29

Abbreviation: nd, not displayed.

Original assignment interchanged.

The data of 2 diols, 136 and 137,^15,57 diacyloxy compound 138,¹⁵ and 3,6-diacyloxy-15-hydroxyfuranoeremophilan-9-one (139)⁵⁴ (Figure 12) are found in Table 29. All have C-15 oxygen functions. Compound 139 is a mixture with a 6-(2-methylbutanoyloxy) derivative.

Figure 12.

Compounds 136-146.

Table 29.

Data of Compounds 136-139.

Compound	136	137	138	139 ^b
(solvent)	¹H (B)	¹H (C)	¹H (C/T)^a	¹H (B)
1	nd	nd	nd	nd
	nd	nd	nd	nd
2	nd	nd	nd	nd
	nd	nd	nd	nd
3	5.40 (br)	4.37 (ddd, 11, 5.5, 5.5)	5.36 (m)	4.36 (br s)
4	–	nd	nd	nd
6	4.77 (m)	2.68 (d, 15.5)	2.79 (d, 17)	6.59 (m)
	–	2.24 (d, 15.5)	2.30 (d, 17)	–
9	nd	nd	nd	–
	nd	nd	nd	–
10	nd	nd	nd	nd
12	7.04 (m)	7.03 (br s)	7.02 (br s)	6.96 (m)
13	2.22 (d, 1.5)	1.89 (d, 1)	1.89 (d, 1)	1.90 (d, 1.5)
14	1.08 (s)	1.01 (s)	1.05 (s)	1.12 (s)
15	3.58 (d, 11)	4.14 (dd, 10, 4)	4.37 (m)	4.34 (dd, 11.5, 6)
	4.08 (d, 11)	3.92 (dd, 10, 3.3)	4.37 (m)	4.73 (dd, 11.5, 3)
3'	–	–	6.02 (dq, 7, 1)	5.75 (br q, 7)
4'	–	–	1.98 (dq, 7, 1)	nd
5'	–	–	1.88 (br s)	nd
3"	–	–	6.02 (dq, 7, 1)	5.75 (br q, 7)
4"	–	–	1.98 (dq, 7, 1)	nd
5"	–	–	1.88 (br s)	nd
[α]_D (solvent)	−14 (EtOH)	nd	nd	nd
Source of compound	Synthetic	Synthetic	Othonna amplexicaulis	Syneilesis palmata
Ref	57	15	15	57

Abbreviation: nd, not displayed.

CDCl₃ or CCl₄.

Mixture with 6-(2-methylbutanoyloxy).

Table 30 gives the data of 3β,6β,15-triol, 140^15,57 and its triacetate, 141 (Figure 12).⁵⁷ Compound 140 prepared by Takahashi's group was sent to Bohlmann's group and its NMR spectrum was measured for comparison.⁵⁷ The fact that the structure was revised from 140 to 170 will be described in Table 38. The data of 140 shown in Table 30 are slightly different, presumably due to the difference in the size of the magnet of the NMR machine used. The reference 14 cited in reference 57, is the error, and should be corrected to reference 16 (in reference 57).

Table 30.

Data of Compounds 140 and 141.

Compound	140	140	140	141	141
(solvent)	¹H (A)	¹H (A)	¹H (C)^a	¹H (B)	¹H (A)
1	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd
2	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd
3	4.29 (ddd, 2.5, 2, 2)	nd	4.45 (ddd, 10, 5, 5)^b	5.43 (br)	5.28 (dt, 8, 5)
4	nd	nd	nd	nd	nd
6	4.59 (t, 1)	4.46 (m)	4.89 (br s)	6.49 (m)	6.28 (m)
9	–	–	2.20 (d-like, 17.5)	nd	nd
	–	–	2.81 (m)	nd	nd
10	nd	nd	nd	nd	nd
12	7.04 (br s)	7.02 (br s)	7.05 (br s)	6.94 (m)	7.18 (m)
13	2.06 (d, 1)	2.03 (d, 1.5)	2.08 (d, 1.1)	1.88 (d, 1.5)	1.87 (d, 1.5)
14	1.48 (s)	0.97 (s)	1.04 (s)	1.09 (s)	1.17 (s)
15	3.95 (d, 9)	nd	3.89 (dd, 10.5, 3)	4.33 (m)	4.29 (d, 5)
	3.95 (d, 9)	nd	4.14 (t, 10.5)	4.33 (m)	4.29 (d, 5)
OAc	–	–	–	1.68 (s)	1.99 (s)
OAc	–	–	–	1.69 (s)	2.02 (s)
OAc	–	–	–	1.79 (s)	2.12 (s)
[α]_D (solvent)	−36.9 (C)	−12 (E)	nd	−35 (E)	nd
Source of compound	synthetic	synthetic	synthetic	synthetic	synthetic
Ref	15	57	57	57	57

Abbreviation: nd, not displayed.

Takahashi's sample sent to Bohlmann and neasured.

Original q.

Table 31 lists the data of 2 diacyloxy-hydroxy ketones, 142 and 143,^27,57 a triacyloxy ketone 144,⁵³ and 2 diacyloxy aldehydes, 145 and 146 (Figure 12).⁵⁷ Three compounds 142-144 are 9-ones, and 145 and 146 15-als. Compound 142 was measured at 75 °C. Compound 143 is a mixture of 3-angeloyloxy-6-senecioyloxy and 3-tigloyloxy-6-angeloyloxy derivatives. The configuration of C-10 of compound 144 is not shown,⁵³ and the solvent for NMR is not shown; probably CDCl₃. Compounds 145 and 146 are a mixture, and the data for a sesquiterpene part are almost the same.⁵⁷

Table 31.

Data of Compounds 142-146.

Compound	142 ^a	143 ^b	144	145 ^d	146 ^d
(solvent)	¹H (B)	¹H (B)	¹H (C)^c	¹H (C)	¹H (C)
1	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd
2	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd
3	5.24 (ddd, 3, 3, 3)	4.36 (br s)	5.16 (m)	5.47 (br)	5.47 (br)
4	nd	nd	nd	nd	nd
6	6.58 (s)	6.49 (m)	nd	6.36 (m)	6.28 (m)
9	–	–	–	nd	nd
10	2.81 (dd, 4, 4)	nd	nd	nd	nd
12	nd	6.96 (m)	7.38 (q, 1)	6.97 (m)	6.97 (m)
13	nd	1.90 (d, 1.5)	nd	1.83 (d, 1.5)	1.83 (d, 1.5)
14	1.29 (s)	1.12 (s)	1.37 (s)	1.04 (s)	1.04 (s)
15	3.72 (dd, 11, 6)	4.34 (dd, 11.5, 6)	4.06 (dd, 11, 8)	9.97 (d, 1.5)	9.97 (d, 1.5)
	3.37 (dd, 11, 6)	4.73 (dd, 11.5, 3)	4.34 (dd, 11, 4)	–	–
3'	nd	5.75 (br q, 7)	nd	6.00 (br q, 7)	6.00 (br q, 7)
4'	nd	nd	nd	nd	nd
5'	nd	nd	nd	nd	nd
2''	nd	nd	–	–	nd
3"	–	–	nd	nd	nd
4"	nd	nd	nd	nd	nd
5"	nd	nd	nd	nd	nd
[α]_D (solvent)	−128.6 (nd)	nd	nd	nd	nd
Source of compound	Othonna triplinervia	Syneilesis palmata	Othonna quinquedentata	Syneilesis palmata	Syneilesis palmata
Ref	27	57	53	57	57

Abbreviation: nd, not displayed.

Measured at 75 °C.

Mixture of 3-angeloyloxy-6-senecioyloxy and 3-tigloyloxy-6-angeloyloxy derivatives.

The configuration of C-10 not determined; solvent not shown, probably C.

Mixture of 145 and 146.

Table 32 compiles the data of four 15-oic acids, 148, 150, and 151,^15,58 and two methyl esters, 147 and 149 (Figure 13).¹⁵ The C-15 positions are oxidized to acids or esters. Compounds 147-149 are monoacyloxy, and 150 and 151 diacyloxy compounds. Compounds 147, 150, and 151 have 3β-(2-methylpropenoyloxy) moieties, while 148 and 149 3β-angeloyloxy. Two ¹³C NMR signals of C-4 and 15 of compound 150 are broad, presumably due to slow movement in the solvent.

Figure 13.

Compounds 147-164.

Table 32.

Data of Compounds 147-151.

Compound	147	148	149	150		151
(solvent)	¹H (C)	¹H (C)	¹H (C)	¹H (B)	¹³C (B)	¹H (B)	¹³C (B)
1	nd	nd	nd	0.90-1.02 (m)	26.3	0.95-1.05 (m)	26.3
	nd	nd	nd	0.90-1.02 (m)	–	0.95-1.05 (m)	–
2	nd	nd	nd	1.81-1.92 (m)	26.7	1.80-1.91 (m)	26.7
	nd	nd	nd	2.13-2.26 (m)	–	2.11-2.26 (m)	–
3	5.32 (ddd, 11, 5.5, 5.5)	5.38 (ddd, 11, 5.5, 5.5)	5.34 (ddd, 11, 5.5, 5.5)	5.75 (dt, 11.4, 5.8)	70.3	5.76 (dt, 11.9, 5.8)	70.4
4	2.96 (d, 5.5)	2.98 (d, 5.5)	2.98 (d, 5.5)	3.33 (d, 5.6)	50^a	3.37 (d, 5.8)	49.8
5	–	–	–	–	41.7	–	41.6
6	2.70 (br d, 15.5)	2.7 (m)	2.70 (br d, 15.5)	6.53 (s)	68.8	6.57 (s)	67.9
7	2.28 (br d, 15.5)	2.7 (m)	2.28 (br d, 15.5)	–	114.7	–	114.8
8	–	–	–	–	150.2	–	150.1
9	–	–	–	1.98 (d, 17.0)	26.3	2.00 (d, 17.2)	26.3
	nd	nd	nd	2.63 (br dd, 17.0, 5.8)	–	2.64 (br dd, 17.2, 5.4)	–
10	nd	nd	nd	2.41-2.50 (m)	36.8	2.37-2.48 (m)	36.8
11	–	–	–	–	119.9	–	119.8
12	7.05 (br s)	7.04 (br s)	7.05 (br s)	6.89 (s)	139.1	6.91 (s)	139.1
13	1.91 (d, 1)	1.91 (d, 1)	1.91 (d, 1)	1.83 (s)	8.7	1.86 (d, 0.8)	8.8
14	0.96 (s)	1.05 (s)	0.96 (s)	1.12 (s)	19.3	1.14 (s)	19.5
15	–	–	–	–	177^a	–	178.3
1'	–	–	–	–	165.7	–	165.7
2'	–	–	–	–	136.7	–	136.7
3'	–	nd	6.04 (qq, 7, 1)	5.15 (quint, 1.2)	125.3	5.16 (quint, 1.3)	125.4
	–	–	–	6.15 (br s)	–	6.16 (br s)	–
4'	5.96 (tq, 1, 1) 2H	nd	1.95 (dq, 7, 1)	1.78 (s)	18.2^b	1.79 (s)	18.2
5'	1.89 (br s)	nd	1.83 (dq, 1, 1)	–	–	–	–
1''	–	–	–	–	167.3	–	167.6
2''	–	–	nd	–	136.3	–	127.4
3"	–	–	–	5.14 (quint, 1.2)	126.1	5.67 (qq, 7.2, 1.3)	139.8
	–	–	–	6.11 (br s)	–	–	–
4"	–	–	–	1.78 (s)	18.4^b	1.97 (dq, 7.2, 1.3)	16.0
5"	–	–	–	–	–	1.83 (quint, 1.4)	20.8
OMe/CO₂H	3.67 (s)	10.05 (br s)	3.66 (s)	–	–	–	–
[α]_D (solvent)	nd	nd	nd	−24.5 (M)		−24.1 (M)
Source of compound	Othonna coronopifolia	Othonna dentata/Othonna coronopifolia	Synthetic	L. cymbulifera		L. cymbulifera
Ref	15	15	15	58		58

Abbreviation: nd, not displayed.

Broad signal.

May be interchanged.

Table 33 presents the data of three diacyloxy 15-oic acids, 152, 153, and 155,^15,57,59 and methyl ester 154 (Figure 13).⁵⁷ Compound 154 is the methyl ester of 153. All have 3β-angeloyloxy groups, and among them 155 has one more angeloyloxy group at C-6β. Compound 152 is a mixture with 161,⁵⁹ 153 with 155 and 159,⁵⁷ 154 with 157 and 160,⁵⁷ and 155 with 154 and 158.⁵⁷ The ¹³C NMR signals of C-1, 9, and 2' of compound 152 were broad.⁵⁹

Table 33.

Data of Compounds 152-155.

Compound	152 ^a		153 ^c	154 ^d	155	155 ^e
(solvent)	¹H (B)	¹³C (B)^b	¹H (T)	¹H (B)	¹H (C)	¹H (T)
1	0.97-1.08	26.4-26.5	nd	nd	nd	nd
	0.97-1.08	–	nd	nd	nd	nd
2	1.82-1.92 (m)	26.9	nd	nd	nd	nd
	2.11-2.26 (m)	–	nd	nd	nd	nd
3	5.65-5.75 (m)	70.1	5.37 (br s)	5.81 (be)	5.50 (ddd, 11, 5.5, 5)	5.37 (br)
4	3.30-3.35 (m)	49.9	nd	nd	nd	nd
5	–	41.6	–	–	–	–
6	6.48 (br s)	68.1	6.37 (m)	6.50 (m)	6.33 (br s)	6.48 (m)
7	–	114.7	–	–	–	–
8	–	150.3	–	–	–	–
9	1.95-2.04 (m)	26.4-26.5	nd	nd	nd	nd
	2.60-2.69 (m)	–	nd	nd	nd	nd
10	2.37-2.50 (m)	37.0	nd	nd	–	–
11	–	119.9	–	–	–	–
12	6.91 (s)	139.1	6.97 (q, 1.5)	6.95 (m)	7.04 (br s)	6.97 (q, 1.5)
13	1.88 (d, 1.1)	9.1	1.81 (d, 1.5)	1.87 (d, 1.5)	1.85 (d, 1)	1.81 (d, 1.5)
14	1.13 (br s)	19.4	1.13 (s)	1.07 (s)	1.09 (s)	1.13 (s)
15	–	179.0	–	–	–	–
1'	–	166.3	–	–	–	–
2'	–	127.8-128.4	–	–	–	–
3'	5.67 (br q, 7.3) 2H	138.5	5.59 (br q, 7)	5.69 (br q, 7)	nd	5.59 (br q, 7)
4'	1.95-2.00 (m)	15.9	nd	nd	nd	nd
5'	1.82-1.85 (m)	20.7	nd	nd	nd	nd
1''	–	176.3	–	–	–	–
2''	2.30 (quint d, 7.2, 6.5)	41.8	nd	nd	–	–
3"	1.34 (dqd, 13.5, 7.3, 6.5)	26.5	nd	nd	nd	nd
	1.79-1.89 (m)	–	–	–	–	–
4"	0.86 (t, 7.3)	12.1	nd	nd	nd	nd
5"	1.20 (d, 7.2)	17.6	nd	nd	nd	nd
OMe/CO₂H	–	–	10.05 (br s)	3.38 (s)	10.10 (br s)	10.05 (br s)
[α]_D (solvent)	nd		nd	nd	nd	nd
Source of compound	L. tongolensis		Syneilesis palmata	Synthetic	Othonna dentata	Syneilesis palmata
Ref	59		57	57	15	57

Abbreviation: nd, not displayed.

Mixture with 161.

Some peaks may be broad.

Mixture with 155 and 159.

Mixture with 157 and 160.

Mixture with 154 and 158.

Table 34 provides the data of 4 methyl esters, 156-158, and 160,^15,27,57 and 15-oic acid 159 (Figure 13).⁵⁷ All have 3β-angeloyloxy groups. Compounds 156 and 157 have 6β-angeloyloxy groups, 158 6β-senecioyloxy, and 159 and 160 3-methylpentanoyloxy groups. Compound 157 is the methyl ester of the corresponding carboxylic acid of the natural product.¹⁵ The configuration of C-3 of compound 156 is 3α-acyloxy (R), others 3β (S). The configurations at C-3' of compound 159 and 160 were not determined.⁵⁷

Table 34.

Data of Compounds 156-160.

Compound	156	157 ^a	157 ^b	158	159 ^c	160 ^d
(solvent)	¹H (C)	¹H (C)	¹H (B)	¹H (C)	¹H (T)	¹H (B)
1	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd
2	nd	nd	nd	nd	nd	nd
	nd	nd	nd	nd	nd	nd
3	5.53 (ddd, 10, 5, 5)	5.46 (ddd, 11, 5.5, 5)	5.81 (be)	5.50 (ddd, 12, 12, 10)	5.37 (br)	5.81 (be)
4	2.99 (d, 4)	nd	nd	2.99 (d, 12)	nd	nd
6	6.43 (br s)	6.30 (br s)	6.63 (m)	6.33 (br s)	6.28 (m)	6.60 (m)
9	nd	nd	nd	2.92 (dd, 17, 8)	nd	nd
	nd	nd	nd	2,30 (br d, 17)	nd	nd
10	nd	nd	nd	2.25 (m)	nd	nd
12	7.04 (br s)	7.02 (br s)	6.95 (m)	nd	6.97 (q, 1.5)	6.95 (m)
13	1.82 (d, 1)	1.85 (d, 1)	1.87 (d, 1.5)	–	1.81 (d, 1.5)	1.87 (d, 1.5)
14	0.99 (s)	0.98 (s)	1.07 (s)	0.99 (s)	1.13 (s)	1.07 (s)
2'	–	–	–	nd	5.59 (br q, 7)	–
3'	6.00 (qq, 7, 1)	nd	5.69 (br q, 7)	nd	nd	5.69 (br q, 7)
4'	1.95 (m)	nd	nd	nd	nd	nd
5'	1.83 (br s)	nd	nd	nd	–	nd
3"	6.00 (qq, 7, 1)	nd	nd	nd	nd	nd
4"	1.95 (m)	nd	nd	nd	nd	nd
5"	1.83 (br s)	nd	nd	–	nd	nd
6'	–	–	–	–	nd	nd
OMe/CO₂H	nd (OMe)	3.64 (s)	3.38 (s)	–	10.05 (br s)	3.38 (s)
[α]_D (solvent)	nd	nd	nd	−36.4 (C)	nd	nd
Source of compound	Synthetic	Synthetic	Synthetic	Othonna arborescens	Syneilesis palmata	Synthetic
Ref	15	15	57	27	57	57

Abbreviation: nd, not displayed.

Natural product is acid.

Mixture with 154 and 160.

Mixture with 155, 159 and 155.

Mixture with 154 and 157.

Table 35 tabulates the data of 2 diacyloxy acids, 161 and 162,^59,60 a methyl ester 163,⁶¹ and an acid 164⁶² (Figure 13). All have 10βH and 3β,6β-substituents. Compound 161 is a mixture with 151, and the ¹³C NMR peaks of C-1, 9, and 2' were broad.⁵⁹ Compound 163 was derived from the natural product, the corresponding acid.⁶¹ Both ¹H and ¹³C NMR signals are tentatively assigned for compound 164.⁶² The signals at δ 2.24 (H-10) and 1.04 (H-3'') for compound 164 recorded in reference 62 should be corrected to 2.44 (qd, 6.6, 5.2) and 1.99 (m), respectively.⁶²

Table 35.

Data of Compounds 161-164.

Compound	161 ^a		162		163	164
(solvent)	¹H (B)	¹³C (B)	¹H (B)	¹³C (B)	¹H (C)	¹H (B)^b	¹³C (B)^b
1	0.97-1.08	26.4-26.5	1.02 (m)	26.4	nd	1.02 (m)	26.4
	0.97-1.08	–	1.02 (m)	–	nd	1.03 (m)	–
2	1.90-2.00 (m)	26.9	1.80 (m)	26.7	nd	1.84 (m)	26.7
	2.18-2.31 (m)	–	2.16 (m)	–	nd	2.24 (m)	–
3	5.88 (br dt, 12.0, 5.8)	70.1	5.64 (dt, 12.2, 6.1)	69.7	5.43 (ddd, 11, 5.5, 5.5)	5.68 (dt, 12.1, 5.5)	69.8
4	3.41-3.45 (m)	50.1	3.30 (br d, 6.1)	49.8	nd	3.32 (br d, 5.5)	49.7
5	–	41.6	–	41.5	–	–	41.6
6	6.61 (br s)	67.4	6.46 (s)	68.2	nd	6.48 (s)	68.2
7	–	115.1	–	114.7	–	–	119.8
8	–	150.1	–	150.2	–	–	150.2
9	1.95-2.04 (m)	26.4-26.5	2.64 (dd, 17.2, 3.7)	26.3	nd	2.65 (dd, 17.6, 4.1)	26.3
	2.60-2.69 (m)	–	1.99 (m)	–	nd	1.95 (m)	–
10	2.37-2.50 (m)	36.9	2.42 (m)	36.9	nd	2.44 (qd, 6.6, 5.2)^c	36.4
11	–	120.0	–	119.8	–	–	114.8
12	6.92 (s)	139.1	6.91 (s)	139.1	nd	6.92 (s)	139.1
13	1.93 (d, 1.2)	8.9	1.85 (s)	8.9	nd	1.87 (d, 1.4)	9.0
14	1.13 (br s)	19.5	1.14 (s)	19.4	1.04 (s)	1.15 (s)	19.5
15	–	179.0	–	177.7	–	–	177.5
1'	–	166.3	–	174.7	–	–	171.4
2'	–	127.8-128.4	2.26 (sext, 7.1)	41.2	2.12 (br d, 7)	1.99 (dd, 14.8, 7.8)	41.5
	–	–	–	–	2.12 (br d, 7)	2.15 (dd, 14.8, 5.9)	–
3'	5.67 (br q, 7.3)	138.5	1.38 (m)	27.0	2.0 (m)	2.04 (m)	31.8
	–	–	1.68 (m)	–	–	–	–
4'	1.95-2.00 (m)	15.9	0.91 (t, 7.1)	11.6	0.93 (d, 6)	1.35 (m)	29.3
	–	–	–	–	–	1.05 (m)	–
5'	1.82-1.85 (m)	20.7	1.07 (d, 7.1)	16.6	0.93 (d, 6)	0.79 (t, 7.4)^d	11.3
6'	–	–	–	–	–	0.97 (d, 6.6)	19.3
1''	–	167.0	–	172.7	–	–	19.3
2''	5.67 (br q, 7.3)	113.9	2.00 (m)	43.4	–	2.09 (dd, 14.6, 8.0)	41.5
	–	–	2.11 (m)	–	–	2.31 (dd, 14.8, 5.9)	–
3"	–	163.8	2.19 (m)	25.7	nd	1.92 (m)^e	32.0
4"	1.66 (qd, 7.4, 1.0)	33.8	0.92 (d, 7.1)	22.5	nd	1.27 (m)	29.4
	nd	11.1	–	–	–	2.01 (m)	–
5"	0.66 (t, 7.4)	–	0.90 (d, 7.1)	22.5	nd	0.81 (t, 7.4)^d	11.4
6'	2.12 (d, 0.9)	19.1	–	–	–	0.89 (d, 6.6)	19.4
OMe/CO₂H	nd	–	nd	–	nd	nd	–
[α]_D (solvent)	nd		−13.1 (C)		nd	−28.1 (C)
Source of compound	L. tongolensis		L. hookeri		Synthetic	L. tongolensis
Ref	59		60		61	62

Abbreviation: nd, not displayed.

Mixture with 151.

Tentative assignment.

Signal at δ 2.24 revised to 2.44.

May be interchanged.

Signal at δ 1.04 revised to 1.92.

Table 36 gives the data of three 3β-acyloxy-15,6-olides, 165-167 (Figure 14).⁶⁰ They can be categorized to furan and/or lactone, but they are included in this chapter. Compound 165 has 2-methylpropanoyloxy group, 166 2-methylpropenoyloxy, and 167 2-methylbutanoyloxy group. These three were isolated from Ligularia hookeri.

Figure 14.

Compounds 165-175.

Table 36.

Data of Compounds 165-167.

Compound	165		166		167
(solvent)	¹H (B)	¹³C (B)	¹H (B)	¹³C (B)	¹H (B)	¹³C (B)
1	0.74 (m)	22.1	0.72 (m)	22.1	0.77 (m)	22.1
	1.56 (m)	–	1.54 (m)	–	1.58 (m)	–
2	1.03 (m)	24.8	1.02 (m)	24.7	1.02 (m)	24.9
	1.61 (m)	–	1.67 (m)	–	1.61 (m)	–
3	5.31 (br s)	65.6	5.38 (br s)	66.3	5.34 (t-like, 2.2)	65.4
4	1.56 (m)	43.0	1.62 (m)	43.2	1.59 (m)	43.1
5	–	40.6	–	40.5	–	40.6
6	4.57 (s)	81.5	4.57 (s)	81.6	4.58 (s)	81.6
7	–	115.1	–	115.1	–	115.1
8	–	150.8	–	150.8	–	150.8
9	1.87 (dd, 17.6, 9.6)	22.7	1.87 (dd, 17.0, 10.6)	22.7	1.88 (dd, 16.0, 10.0)	22.7
	2.04 (dd, 17.6, 6.8)	–	2.10 (dd, 17.0, 7.3)	–	2.11 (dd, 16.0, 7.0)	–
10	1.58 (m)	36.7	1.57 (m)	36.8	1.58 (m)	36.8
11	–	120.4	–	120.4	–	120.5
12	6.84 (s)	138.7	6.85 (s)	138.8	6.85 (s)	138.7
13	1.93 (s)	8.2	1.93 (s)	8.3	1.93 (s)	8.2
14	1.19 (s)	23.1	1.18 (s)	23.2	1.20 (s)	23.1
15	–	171.8	–	171.7	–	171.8
1'	–	175.5	–	166.4	–	175.0
2'	2.31 (sept, 7.0)	34.4	–	136.8	2.22 (sext, 6.2)	41.6
3'	1.06 (d, 7.0)	19.1^a	5.18 (quint, 1.3)	125.4	1.65 (m)	27.1
	–	–	6.08 (s)	–	1.36 (quint, 4.7)	–
4'	1.04 (d, 7.0)	19.0^a	1.93 (d, 1.3)	18.5	0.85 (t, 6.6)	11.6
5'	–	–	–	–	1.06 (d, 7.0)	16.7
[α]_D (solvent)	+24.6 (C)		+15.4 (C)		+39.0 (C)
Source of compound	L. hookeri		L. hookeri		L. hookeri
Ref	60		60		60

Abbreviation: nd, not displayed.

May be interchanged.

Table 37 shows the data of 3β-angeloyloxyfuranoeremophilan-15,6α-olide (168)^27,57,60,63 and 3β-(3-methylpentanoyloxy)furanoeremophilan-15,6-olide (169)⁶² (Figure 14). Compound 168 in reference 27 is a mixture with 166. The ¹³C NMR data for compound 168 in reference 63 were revised by comparing with those of similar compounds.

Table 37.

Data of Compounds 168 and 169.

Compound	168 ^a	168	168		168		168		169
(solvent)	¹H (C)	¹H (B)	¹H (C)	¹³C (C)^c	¹H (C)	¹³C (C)	¹H (B)	¹³C (B)	¹H (B)	¹³C (B)
1	nd	nd	1.85 (m)	22.3	1.49 (m)	22.2	0.72 (m)	22.1	0.77 (m)	22.2
	nd	nd	2.05 (m)	–	2.09 (m)	–	1.57 (m)	–	1.60 (m)	–
2	nd	nd	1.23 (m)	25.1	1.87 (m)	25.1	1.06 (m)	24.8	1.06 (m)	24.9
	nd	nd	1.50 (m)	–	2.01 (m)	–	1.67 (m)	–	1.63 (m)	–
3	5.55 (ddd, 3, 3, 3)	5.43 (br s)	5.52 (br s)	65.2	5.53 (br s)	65.2	5.40 (br s)	65.4	5.38 (quint, 1.9)	65.4
4	2.51 (d, 3)	nd	2.53 (br s)	43.7	2.54 (d, 2.9)	43.7	1.55 (m)	36.7	1.61 (m)	43.1
5	–	–	–	40.9	–	40.9	–	40.4	–	40.7
6	5.09 (br s)	4.58 (m)	5.07 (s)	82.4	5.08 (s)	82.4	4.56 (s)	81.5	4.58 (s)	81.7
7	–	–	–	114.5	–	114.5	–	115.1	–	115.1
8	–	–	–	150.6	–	150.6	–	150.8	–	150.8
9	2.61 (dd, 17, 10)	nd	2.68 (m)	22.7	2.61 (dd, 17.6, 9.9)	22.7	1.86 (dd, 17.6, 9.2)	22.6	1.87 (m)	22.7
	2.73 (dd, 17, 8)	nd	2.68 (m)	–	2.71 (dd, 17.6, 7.7)	–	2.09 (dd, 17.6, 7.0)	–	2.14 (dd, 14.4, 6.3)	–
10	2.37 (m)	nd	2.36 (m)	37.0	2.37 (m)	36.9	1.56 (m)	43.1	1.59 (m)	36.8
11	–	–	–	120.1	–	120.1		120.4	–	120.4
12	nd	6.88 (m)	7.07 (s)	138.9	7.08 (s)	138.9	6.84 (s)	138.8	6.85 (s)	138.8
13	nd	1.93 (d, 1.5)	2.01 (s)	8.2	2.01 (s)	8.2	1.92 (s)	8.3	1.93 (d, 1.1)	8.3
14	1.53 (s)	1.21 (s)	1.50 (s)	23.3	1.52 (s)	23.4	1.18 (s)	23.2	1.23 (s)	23.1
15	–	–	–	172.6	–	172.8	–	171.8	–	171.7
1'	–	–	–	166.8	–	166.8	–	166.6	–	171.9
2'	–	–	–	127.5	–	127.4	–	128.0^d	1.98 (dd, 14.4, 7.8)	41.9
	–	–	–	–	–	–	–	–	2.10 (dd, 17.4, 7.3)	–
3'	nd	5.71 (br q, 7)	6.06 (dq)^b	138.9	6.07 (qq, 7.3, 1.5)	139.2	5.66 (qq, 7.3, 1.5)	138.7	1.88 (m)	32.3
4'	nd	2.01 (dq, 7, 2)	2.00 (dq)^b	15.7	2.00 (dq, 7.3, 1.5)	15.8	2.01 (dq, 7.3, 1.5)	15.8	1.10 (m)	29.4
	–	–	–	–	–	–	–	–	1.30 (m)	–
5'	nd	1.80 (q, 2)	1.85 (br s)	20.7	1.88 (quint, 1.5)	20.8	1.78 (quint, 1.5)	21.0	0.79 (t, 7.4)	11.4
6'	–	–	–	–	–	–	–	–	0.89 (d, 6.9)	19.3
[α]_D (solvent)	+37.5 (nd)	+18 (E)	+47.4 (C)		nd		nd		+17.6 (C)
Source of compound	Othonna lobata	Synthetic	L. lapathifolia		L. hookeri		L. hookeri		L. tongolensis
Ref	27	57	63		60		60		62

Abbreviation: nd, not displayed.

Mixture with 166.

J not shown.

Assingment revised.

Overlapped with solvent.

The data of 6α,15-epoxyfuranoeremophilan-3β-ol (170),^53,57 6α,15-epoxyfuranoeremophilan-3-one (171),⁵⁷ and four 3β-acyloxy-6α,15-epoxyfuranoeremophilane, 172-175 (Figure 14).^27,53,57,58 are listen in Table 38. All have epoxide structure between C-6 and C-15. Compound 170 was originally proposed as triol 140 by Bohlmann,⁵³ but later revised to have 6α,15-epoxide structure,⁵⁷ and it was found to be easily prepared from 140 through acid treatment. Compound 174 has 10αH and 9-oxo group with 6αH, which can be derived from compound 142 through hydrolysis, cyclization, and isomerization.²⁷ The configuration at C-3' of compound 175 was not determined.⁵⁸

Table 38.

Data of Compounds 170-175.

Compound	170	170 ^b	170	171	172	173	173	174	175
(solvent)	¹H (C)^a	¹H (C)	¹H (B)	¹H (B)	¹H (C)	¹H (B)^c	¹H (C)	¹H (B)	¹H (B)	¹³C (B)
1	nd	nd	nd	nd	nd	nd	nd	nd	0.90-0.98 (m)	22.7
	nd	nd	nd	nd	nd	nd	nd	nd	1.80-1.91 (m)	–
2	nd	nd	nd	nd	nd	nd	nd	nd	1.22-1.34 (m)	25.6
	nd	nd	nd	nd	nd	nd	nd	nd	1.51-1.60 (m)	–
3	4.25 (dd, 5, 2)	4.26 (br s)	3.56 (br s)	–	5.33 (ddd, 3, 3, 3)	5.31 (br dd, 5, 2)	5.32 (br s)	5.10 (ddd, 3, 3, 3)	5.04 (br s)	67.6
4	nd	nd	nd	nd	2.18 (m)	nd	nd	1.3 (m)	1.63 (ddd, 11.4, 7.2, 2.5)	41.6
5	–	–	–	–	–	–	–	–	–	42.1
6	4.57 (t, 1)	4.55 (m)	4.54 (m)	4.43 (m)	4.61 (br s)	4.57 (br s)	4.58 (m)	4.56 (s)	4.55 (s)	81.2
7	–	–	–	–	–	–	–	–	–	119.9
8	–	–	–	–	–	–	–	–	–	148.4
9	nd	nd	nd	nd	2.59 (dd, 17, 8)	nd	nd	–	2.11-2.20 (m)	23.2
	nd	nd	nd	nd	2.59 (dd, 17, 8)	nd	nd	–	2.27 (br dd, 16.9, 7.2)	–
10	nd	nd	nd	nd	2.18 (m)	nd	nd	2.17 (m)	1.81-1.91 (m)	37.9
11	–	–	–	–	–	–	–	–	–	120.8
12	7.01 (br s)	7.02 (br s)	6.99 (m)	6.94 (m)	nd	7.00 (q, 1)	7.01 (m)	nd	6.98 (s)	138.1
13	2.03 (d, 1)	2.01 (d, 1.5)	2.14 (d, 1.5)	2.06 (d, 1.5)	nd	2.00 (d, 1)	2.02 (d, 1.5)	nd	2.14 (d, 1.1)	8.7
14	1.45 (s)	1.44 (s)	1.40 (s)	0.78 (s)	1.41 (s)	1.37 (s)	1.40 (s)	1.10 (s)	1.29 (s)	22.6
15	3.92 (m)	3.84 (m)	3.70 (t, 7)	3.85 (t, 8)	3.94 (dd, 8, 8)	3.91 (dd, 7.5, 7.5)	3.92 (t, 7.5)	3.17 (dd, 12, 9)	3.89 (t, 7.2)	67.2
	3.92 (m)	4.00 (m)	3.87 (dd, 11.5, 7)	4.15 (dd, 11, 8)	3.70 (dd, 12, 8)	3.68 (dd, 11, 7.5)	3.67 (dd, 11, 7.5)	3.62 (dd, 12, 2)	3.81 (dd, 11.4, 7.2)	–
1'	–	–	–	–	–	–	–	–	–	171.9
2'	–	–	–	–	–	–	–	–	1.87-1.96 (m)	41.8
	–	–	–	–	–	–	–	–	2.08-2.15 (m)	–
3'	–	–	–	–	nd	5.75 (qq, 7, 1)	6.07 (q-like, 7)	nd	1.79-1.95 (m)	32.0
4'	–	–	–	–	nd	1.95 (dq, 7, 1)	nd	nd	1.05 (dquint, 13.5, 7.4)	29.4
	–	–	–	–	–	–	–	–	1.22 (dqd, 13.5, 7.5, 5.4)	–
5'	–	–	–	–	–	1.79 (dq, 1, 1)	nd	nd	0.76 (t, 7.5)	11.4
6'	–	–	–	–	–	–	–	–	0.83 (d, 6.5)	19.3
[α]_D (solvent)	nd	−27 (E)	−27 (E)	−31 (C)	+16.2 (nd)	nd	−18 (E)	nd	−11.2 (M)
Source of compound	Synthetic	Synthetic	Synthetic	Synthetic	Othonna lobata	Othonna quinquedentata	Syneilesis palmata	nd	L. tongolensis
Ref	53, 57	57	57	57	27	53	57	27	58

Abbreviation: nd, not displayed.

Solvent not shown, but probably CDCl₃.

[α]_D −30 (E) also shown.

Solvent not shown, but probably C₆D₆.

Finally, 2 conformations of 10β-H furanoeremophilanes are quickly introduced here for better understanding (Figure 15). In the previous review,³ 2 conformations, namely, “steroid-like” and “non-steroid-like” conformations were displayed using ligularol and 6-epi-ligularol. In steroid-like conformation, 3β-O function adopts axial position, but in non-steroid-like conformation, equatorial position. The conformation for compounds having more functionalities is easily determined by the coupling constants and/or nuclear overhauser effect (NOE) measurements. However, those of less substituted compounds, such as ligularol and its 6-epimer, are not easy, in case the temperature dependent NMR measurement is necessary to see the 2 conformers, in some cases at lower temperature (preferably in CDCl₃), and in the other cases at higher temperature (sometimes in C₆D₆ solution).

Figure 15.

Two conformations of 10βH-furanoeremophilanes.

Footnotes

Acknowledgements

The author thanks laboratory staff members engaged in these projects acquiring NMR data. Special thanks are due to Dr Yasuko Okamoto and Prof. Masakazu Sono, Tokushima Bunri University, Prof. Yoshinosuke Usuki, Osaka Metropolitan University, and Emeritus Prof. Chiaki Kuroda, Rikkyo University, for their help to check the references appeared in this review.

Declaration of Conflicting Interests

The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Motoo Tori

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Cumulative Data of 1 H and 13 C NMR Signals and Specific Rotations of Eremophilane Sesquiterpenoids. 4. 10H-3-O-Furanoeremophilanes

Abstract

Keywords

Introduction

Discussion

Footnotes

Acknowledgements

Declaration of Conflicting Interests

Funding

ORCID iD

References