反应详情

2α, 3α-Epoxy-5α-pregnane-11,20-dione (502 mg) was dissolved in chloroform (30 ml.) and the solution was treated with hydrobromic acid (48 %, 10 ml.). The mixture was stirred vigorously at room temperature for 30 minutes, and then poured into chloroform. The organic solution was washed with dilute sodium bicarbonate solution, then with water, and was then dried over sodium sulphate and evaporated to give a crystalline residue which was recrystallised from acetone-ether to give 2β-bromo-3α-hydroxy-5α-pregnane-11,20-dione (483 mg.) as colourless crystals, m.p. 206°-210° [α]D + 106°.

1. washThe organic solution was washed with dilute sodium bicarbonate solution
2. dry with materialwith water, and was then dried over sodium sulphate
3. customevaporated
4. customto give a crystalline residue which
5. customwas recrystallised from acetone-ether