Bromination of 3α,12α-diacetoxypregnan-20-one ethylene ketal provided in good yield the corresponding 21-monobromo compound. This product, on acid hydrolysis and subsequent acetolysis, gave the known 3α,12α,21-triacetoxypregnan-20-one. Acid hydrolysis of the bromoketal, followed by Faworsky rearrangement, led to 3α,12α-diacetoxy-17α-methyletiocholanic acid methyl ester.
3α,12α-
二乙酰氧
孕酮-20-烯基
乙烷基
溴化反应,得到对应的21-单
溴化合物,收率良好。该产物在酸
水解和随后的乙酰化反应中,生成已知的3α,12α,21-三乙酰氧
孕酮-20-酮。对
溴代烷基的酸
水解,随后进行Faworsky重排反应,得到3α,12α-
二乙酰氧-17α-甲基
硫代
胆酸甲酯。