Two polyhydroxylated Δ13-17,17-dialkyl-18-norsteroids were prepared by BF3·Et2O/Ac2O-promoted regioselective E-ring cleavage/ 1-2 hydride shift/ Wagner-Meerwein rearrangement of furostanols derived from the steroid sapogenins diosgenin and sarsasapogenin. Details of the spectroscopic characterization are discussed.
(a) DurbeckHW, BukerI. (1980) Studies on anabolic-steroids. The mass-spectra of 17-α-methyl-17-β-hydroxy-1,4-androstadien-3-one (dianabol) and its metabolites. Biomedical Mass Spectrometry, 7, 437–445.
2.
BiH, MasséR, JustG. (1992) Studies on anabolic steroids. 9. Tertiary sulfates of anabolic 17α-methyl steroids: synthesis and rearrangement. Steroids, 57, 306–312.
3.
De BrabandereVI, ThienpontLM, StocklD, De LeenheerAP. (1997) 13C-NMR and mass spectral data of steroids with a 17,17-dialkyl-18-nor-13(14)-ene substructure. Journal of Lipid Research, 38, 780–789.
4.
ShapiroEL, SteinbergM, GouldD, GentlesMJ, HersogHL, GilmoreM, CharneyW, HearsbergEB, MandelL. (1959) Wagner-Meerwein rearrangements. III. Further aspects of acid-catalyzed opening of steroidal 16,17-epoxides. Journal of the American Chemical Society, 81, 6483–6486.
5.
GirdharNK, IzarMPS, KumarR, SinghR, SinghG (2001) Highly efficient Lewis acid catalyzed, one step conversions of 16α,17α-epoxy-3β-hydroxypregn-5-en-20-one to D-homosteroid and Δ13-steroids. Tetrahedron, 57, 7199–7204.
6.
(a) Pri-BarI, StilleJK. (1982) Acylative cleavage of ethers catalyzed by triorganotin halides and palladium (II) complexes. Journal of Organic Chemistry, 47, 1215–1220.
7.
YadavVK, FallisAG. (1986) Regioselective cleavage of 2-methyltetrahydrofuran: a versatile synthesis of 1-halo-4-pentanols and 4-halo-1-pentanols. Journal of Organic Chemistry, 51, 3372–3374.
8.
BharS, RanuBC. (1995) Zinc-promoted selective cleavage of ethers in presence of acyl chloride. Journal of Organic Chemistry, 60, 745–747.
9.
KangJ, KimSH. (2000) A facile synthetic protocol for the preparation of 4-halobutyl benzoates via carbon-oxygen bond cleavage of THF. Bulletin of the Korean Chemical Society, 21, 611–612.
10.
MalladiRR, KabalkaGW. (2002) One-pot synthesis of Ω-chloroesters via the reaction of acid chlorides with tetrahydrofuran in the presence of trichloroborane. Synthetic Communications, 32, 1997–2001.
11.
GuoQ, MiyajiT, HaraR, ShenB, TakahashiT. (2002) Group 5 and group 6 metal halides as very efficient catalysts for acylative cleavage of ethers. Tetrahedron, 58, 7327–7334.
12.
KwonDW, KimYH, LeeK. (2002) Highly regioselective cleavages and iodinations of cyclic ethers utilizing SmI2. Journal of Organic Chemistry, 67, 9488–9491.
13.
(a) Iglesias-ArteagaMA, Ledesma-RodríguezFL, Méndez-StivaletJM, Flores-AlamoM. (2005) Reaction of a 5α-bromo-6β,19-epoxysteroid with BF3·Et2O/Ac2O. An evidence of a cyclic bromonium cation. Tetrahedron Letters, 46, 2771–2774.
14.
GonzálezAG, FranciscoCG, FreireR, HernándezR, SalazarJA. SuárezE. (1974) Stereoselective opening of ring E in furostan sapogenins. An efficient route to 16,22R,26-hydroxy steroids. Tetrahedron Letters, 15, 4289–4292.
15.
(a) Iglesias-ArteagaMA, Pérez-MartínezCS, Coll-ManchadoF. (2001) Main NMR characteristics of synthetic (25R)-5α-furostanes. Journal of Chemical Research (S), 34–35.
16.
Iglesias-ArteagaMA, Pérez-GilR, Leliebre-LaraV, Pérez-MartínezCS, Coll-ManchadoF. (1996) Synthesis and biological activity of (22R,25R)-5α-furostan-2α,3α,26-triol. Journal of Chemical Research (S), 504–505.
(a) DoukasHM, FontaineTD. (1953) Acid-catalyzed reduction of spirostanols and spirostenols by lithium aluminum hydride. Journal of the American Chemical Society, 75, 5355–5356.
20.
PettitGR, BowyerWJ. (1960) Aluminum Chloride-Catalyzed opening of the steroidal sapogenin spiroketal system. Journal of Organic Chemistry, 25, 84–86.
21.
SiegfriedB, BrunckA, JautelatR.WinterfeldtE. (2000) Synthesis of cytostatic tetradecacyclic pyrazines and a novel reduction-oxidation sequence for spiroketal opening in sapogenins. Helvetica Chimica Acta, 83, 1854–1880.
