PREPARATION METHOD OF 3ALPHA-HYDROXY-3BETA-SUBSTITUTED-PREGNANE

摘要

PROBLEM TO BE SOLVED: To provide a simple method for converting a pregnane-3,20-dione compound into a 3α-hydroxy-3β-substituted-pregnane. SOLUTION: An unprotected dione is chemoselectively and stereoselelctively converted into a 3(R)-pregnane-3-spiro-2'-oxiran-20-one intermediate by the selective use of a reagent. This intermediate can be regioselectively converted by the second-step reaction into a 3α-hydroxy-3β-substituted-20-one form, which can be further modified at its 20-keto position. Through this method, each ketone group is independently treated. COPYRIGHT: (C)2006,JPO&NCIPI