反应详情

2α, 3α-Epoxy-5α-pregnane-11,20-dione (660 mg.) was dissolved in ether (70 ml.) and 2-bromoethanol (1 ml.) added to the solution. Concentrated sulphuric acid (0.5 ml.) was then added and the mixture stirred at room temperature for one-half hour. 10% Potassium bicarbonate solution (18 ml.) was added and when effervescence had ceased the aqueous layer was removed and extracted with ether (20 ml.). The combined organic extracts were washed with water (100 ml.), dried over anhydrous sodium sulphate and evaporated in vacuo to a pale yellow oil (794 mg.) which was purified by preparative tlc. The main band (RF ~ 0.3) gave 2β-bromo-3α-hydroxy-5α-pregnane-11,20-dione (230 mg.), m.p. 172°-3°C identical with a previously prepared sample.

1. customwas removed
2. extractionextracted with ether (20 ml.)
3. washThe combined organic extracts were washed with water (100 ml.)
4. dry with materialdried over anhydrous sodium sulphate
5. customevaporated in vacuo to a pale yellow oil (794 mg.) which
6. customwas purified by preparative tlc