Based on the regioselective acetylation-bromination, unimolecular elimination, epoxidation from pregnanetriol, 16, 17- epoxy-pregn-3S, 20S- diol diacetate was obtained. Then through ring cleavage by Grignard reagent, we got the key intermediate, 16β-methyl-pregn-3, 17, 20-triol in 4 steps with 54% overall yield.
2.以剑麻皂甙元的降解产物孕甾三醇为起始原料,经过区域选择性乙酰化溴代、单消除、环氧化反应得到16, 17-环氧-孕甾-3S, 20S-二醇二乙酸酯,然后经过格氏试剂开环反应以共4步反应,以54%的收率得到关键中间体16β-甲基-孕甾-3, 17, 20-三醇,对β-米松药物中间体Ⅰ的合成也进行了尝试合成研究。
参考来源 - Betamethasone中间体的合成及研究·2,447,543篇论文数据，部分数据来源于NoteExpress
应用推荐