反应详情

A solution of acetate 9a (75 mg) in ethanol (10 ml) containing 5% aqueous NaOH (1 ml) was set aside for 24 h and then the solvent was evaporated in vacuo. The residue was taken in ethyl acetate (30 ml) and washed consecutively with 5% HCl, water, and saturated aqueous NaHCO3. Evaporation of the solvent gave (20S) 3b,25-dihydroxycholesta-5,7-diene 9b (74 mg) which was used for the next step without purification; λmax 240, 249, 260 and 272 nm; high resolution mass spec. for C27H44O2 calcd.: 400.3341(M+); found: 400.3334(100%), 398.3162(M+ --H2O, 11%), 385.3101(M+ --CH3, 14%), 380.3086, 24%), 367.3013(M+ --CH3 --H2O, 67%).

1. customthe solvent was evaporated in vacuo
2. washwashed consecutively with 5% HCl, water, and saturated aqueous NaHCO3
3. customEvaporation of the solvent