17nat, a hexacyclic steroid bearing the requisite functionality and spiroketal stereochemistry of the North portion of the cephalostatin family is described. The key reaction involves CrCl2 mediated reductive cleavage of a tertiary bromide which is beta to three alkoxy groups.
描述了将醛4转化为17nat(一种具有必要功能和头颅
抑素家族北部部分的螺状体立体
化学的六环类
固醇)的方法。关键反应涉及CrCl 2介导的叔
溴化物的还原裂解,后者是三个烷氧基的β。