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31.
Preparation and selected data of 2-pentyl-N-hydroxypiperidine (4): Prepared by dropwise addition of pentylmagnesium bromide (9.6 g, 55 mmol) in diethylether (100 mL) to a solution of nitrone 3 [10a] (5.0 g, 50 mmol) in dicholoromethane (100 mL) at 20°C. After stirring for 1 h, a saturated solution of NH4Cl (100 mL) was added to the reaction mixture and extracted with diethyl ether (2 × 50 mL). Colorless liquid, 7.0 g, 41 mmol, 82%, bp0.8mbarHg100°C; m/z 171 [M+]; Found: C, 70.1; H, 12.2; N, 8.1. C10H21NO requires C, 70.12; H, 12.36; N, 8.18%.); νmax (neat) 3210, 2935, 2853, 1455, 1377, 1355, 1260, 1229, 1177, 1103, 1064, 1035, 986, 949, 862, 828, 775 and 729 cm−1; δH (500 MHz, CDCl3, +25°C) 7.24 (1H, br, OH), 3.30 (1H, apparent d, J = 10.1 Hz), 2.49 (1H, ddd, J = 3.0, 10.3, 13.1 Hz), 2.27-2.20 (1H, m), 2.04-1.95 (1H, m), 1.87-1.82 (1H, m), 1.75-1.50 (3H, m), 1.40-1.10 (9H, m), 0.89 (3H, t, J = 7.0 Hz); δC (125 MHz, CDCl3, +25 °C) 67.8 (d), 59.7 (t), 33.2 (t), 32.3 (t), 31.0 (t), 25.9 (t), 25.5 (t), 23.8 (t), 22.7 (t), 14.1 (q).
32.
Selected data of 2-butoxy-7-pentyl-hexahydro-2H-isoxazolo[2,3-a]pyridines (7a): m/z 269 [M+]; Found: C, 71.2; H, 11.5; N, 5.1. C16H31NO2 requires C, 71.33; H, 11.60; N, 5.20%.); νmax (neat) 2954, 2930, 2862, 1462, 1447, 1352, 1250, 1193, 1123, 1088, 943, 909, 849, 821 and 730 cm−1; δH (500 MHz, CDCl3, +25°C) 5.27 (1H, d, J = 4.8 Hz), 3.74 (1H, td, J = 6.7, 9.5 Hz), 3.77-3.67 (1H, m), 3.36 (1H, td, J = 6.7, 9.2 Hz), 2.54-2.45 (1H, m), 2.40-2.30 (1H, m), 1.97-1.70 (5H, m), 1.54 (2H, quint, J = 7.0 Hz), 1.52-1.46 (1H, m), 1.40-1.10 (11 H, m), 0.90 (3H, t, J = 7.3 Hz), 0.88 (3H, t, J = 7.0 Hz); δC (125 MHz, CDCl3, +25°C) 102.5 (d), 67.6 (t), 60.9 (d), 57.5 (d), 37.4 (t), 33.9 (t), 32.1 (t), 31.7 (t), 28.8 (t), 25.2 (2C, t), 22.6 (t), 19.3 (t), 18.6 (t), 13.9 (2C, q). (7b): An analytical sample of 7b was not prepared as a result of the difficulty in chromatographic separation. The sample of 7b, containing 3-5% of the major isomer (7a) gave the following spectral data: δH (500 MHz, CDCl3, +25°C) 5.09 (1H, dd, J = 3.4, 6.4 Hz), 3.80 (1H, td, J = 7.3, 9.2 Hz), 3.40-3.27 (2H, m), 3.07-2.97 (1H, m), 2.46-2.40 (1H, m), 2.25-2.15 (1H, m), 2.04-1.98 (1H, m), 1.80-1.15 (17 H, m), 0.90 (3H, t, J = 7.0 Hz), 0.88 (3H, t, J = 7.0 Hz);); δC (125 MHz, CDCl3, +25°C) 100.8 (d), 68.4 (t), 60.9 (d), 57.6 (d), 37.5 (t), 33.8 (t), 32.5 (t), 31.6 (t), 27.8 (t), 25.4 (t), 24.8 (t), 22.5 (t), 19.8 (t), 19.6 (t), 14.0 (q). 13.9 (q).
