反应详情

温度

4 °C

To 3β-azido-5-cholestene (14, 3.30 g, 8.02 mmol) in dry diethyl ether (150 mL) at 4° C. was added lithium aluminum hydride (4.60 g, 121.18 mmol) in three equal portions. The reaction was maintained at 4° C. for 30 min, warmed to 23° C., and stirred for an additional 1.5 h. The reaction was quenched by addition of diethyl ether (50 mL) followed by careful dropwise addition of deionized H2O (60 mL). The organic layer was washed with saturated aqueous NaCl (2×100 mL), dried over anhydrous Na2SO4, and concentrated in vacuo to afford 2.90 g (85%) of crude 3β-amino-5-cholestene. This aminosteroid was dissolved in dry THF (150 mL), and diisopropylethylamine (2.61 mL, 15.03 mmol) was added. 2-Nitrobenzenesulfonyl chloride (2.20 g, 9.92 mmol) in dry THF (40 mL) was added by addition funnel over 30 min. After 2 h at 23° C., solvents were removed in vacuo, CH2Cl2 was added (75 mL), and this organic solution was washed with aqueous NaHCO3 (10%, 1×100 mL) and saturated aqueous NaCl (2×100 mL). The organic extracts were dried over anhydrous Na2SO4 and concentrated in vacuo to yield a crude yellow solid. Recrystallization (CH2Cl2/MeOH, 1:5) followed by flash column chromatography (EtOAc/hexanes, 1:5) afforded off-white 15 (3.50 g, 83%), mp 202-203° C.; 1H NMR (300 MHz, CDCl3) δ 8.16-8.12 (m, 1H), 7.86-7.82 (m, 1H), 7.75-7.67 (m, 2H), 5.19 (s, 1H), 5.16 (s, 1H), 3.28-3.18 (m, 1H), 2.18-0.83 (m, 40H), 0.63 (s, 3H); 13C NMR (75.41 MHz, CDCl3) δ 148.1, 139.9, 135.4, 133.6, 133.1, 131.0, 125.6, 122.7, 56.9, 56.3, 55.2, 50.2, 42.5, 40.3, 39.9, 39.7, 38.0, 36.6, 36.4, 36.0, 32.0, 31.9, 30.2, 28.4, 28.2, 24.4, 24.0, 23.0, 22.8, 21.1, 19.4, 18.9, 12.0; IR (film) νmax 3331, 2936, 2359, 1541 cm−1; CI m/z 571.3567 (MH+, C33H51N2O4S requires 571.3569).

1. temperaturewarmed to 23° C.
2. customThe reaction was quenched by addition of diethyl ether (50 mL)
3. additionfollowed by careful dropwise addition of deionized H2O (60 mL)
4. washThe organic layer was washed with saturated aqueous NaCl (2×100 mL)
5. dry with materialdried over anhydrous Na2SO4
6. concentrationconcentrated in vacuo