作者:Aryeh A. Frimer、Gladis Aljadeff、Sara Rubinstein、Haim Breitart
DOI:10.1002/ardp.19973300502
日期:——
20‐dione 20‐ethylene ketal (7) resulted in the saponification of the ester with the concomitant formation of 2,21‐dihydroxypregna‐1,4‐diene‐3,20‐dione 20‐ethylene ketal (8) Continued BCA at ambient temperature, converts the latter to 1,21‐dihydroxy‐2‐oxaprogesterone 20‐ethylene ketal (9), which is reduced by NaBH4 to the 2‐oxasteroid, 21‐hydroxy‐2‐oxaprogesterone 20‐ethylene ketal (10). Treatment of
21-乙酰氧基孕酮-5-烯-3,20-二酮20-乙烯缩酮(7)的A-环的低温碱催化自氧化(BCA)导致酯的皂化,同时形成2,21- dihydroxypregna-1,4-diene-3,20-dione 20-ethylene ketal (8) 在环境温度下持续进行 BCA,将后者转化为 1,21-dihydroxy-2-oxaprogesterone 20-ethylene ketal (9),后者被还原由 NaBH4 转化为 2-氧杂类固醇,21-羟基-2-氧代孕酮 20-乙烯缩酮 (10)。用酸水溶液处理烯醇 8、内酯 9、9 和内酯 10 生成相应的脱保护类似物 2,21-二羟基孕酮 - 1,4-二烯 - 3,20-二酮(烯醇 11)、1,21 - 二羟基 - 2 -oxaprogesterone (lactol 12), 和 2-oxacortexone (2-oxadesoxycorticosterone