reaction sequence including hydroxyl group-assisted cyclopropanation, C(17)-oxidation, B-ring aromatization, C(17)-reduction, and methyl ether cleavage has been devised to convert 2 into 12. The synthesis of 19 took advantage of a facile isomerization of vinyl(benzyl)cyclopropane derivatives 6–11 into the corresponding β-bridged analogues 13–18 over molecular sieves.
包括羟基辅助的
环丙烷化,C(17)-氧化,B环芳构化,C(17)-还原和
甲醚裂解的五步反应序列已被设计为将2转化为12。19的合成利用了
分子筛将
乙烯基(苄基)
环丙烷衍
生物6-11轻松异构化为相应的β-桥联类似物13-18的优势。