The invention relates to processes for preparing 3α-O-linked steroids including 3α-O-linked-androst-5-ene steroids and 3α-O-linked-5a-androstane steroids. In one process a 3α,4α-epoxy androst-5-en-17-one is predominately reduced at the epoxy moiety wherein reduction of the 3α,4α epoxy functional group occurs preferentially at position C4 with retention of configuration at position C3 to provide a 3α-O-linked-androst-5-ene steroid. In another process, conditions are provided for inversion of configuration of a 3β-hydroxy-androst-5-ene steroid by the Mitsunobu reaction to provide a 3α-O-linked-androst-5-ene steroid with reduced amounts of 3α,5α-cycloandrostane side-product impurities.
该发明涉及制备3α-O-连接类
固醇的过程,包括3α-O-连接-雄烯类
固醇和3α-O-连接-
5α-雄烷类
固醇。在一个过程中,3α,4α-环氧基雄-5-烯-17-酮主要在环氧基团处还原,其中3α,4α-环氧官能团的还原优先发生在C4位置,并保留C3位置的构型,以提供3α-O-连接-雄烯类
固醇。在另一个过程中,通过Mitsunobu反应提供条件,使3β-羟基雄-5-烯类
固醇的构型发生倒置,以提供含有减少量3α,5α-环雄烷副产物杂质的3α-O-连接-雄烯类
固醇。