反应详情

A solution of 9α-bromo-11β-hydroxyandrost-4-ene-3,17-dione (III, 2.00 g), thioglycolic acid (2.0 ml) in THF (20 ml) and water (5 ml) is stirred under nitrogen at 20°-25°. A chromous sulfate solution (1.4 M, 5.5 ml) is added and the two-phase system is stirred. After four hours, another 4.5 ml of chromous sulfate solution is added and the mixture stirred overnight. The mixture is diluted with water and extracted with ethyl acetate. The ethyl acetate extracts are washed with water, a diluted sodium hydroxide solution, water and saline. The organic phase is dried over sodium sulfate and concentrated to a solid. The solid is crystallized from benzene-hexane to give a first crop of crystals of the title compound (1.38 g, 83.5% chemical yield) which are measured to be 99% pure as measured by GLC and is identical to an authentic sample.

1. stirringthe mixture stirred overnight
2. extractionextracted with ethyl acetate
3. washThe ethyl acetate extracts are washed with water
4. dry with materialThe organic phase is dried over sodium sulfate
5. concentrationconcentrated to a solid
6. customThe solid is crystallized from benzene-hexane