NOVEL PROCESS FOR STEREOSELECTIVE REDUCTION OF BETA-KETOESTERS

摘要

In one aspect, the invention provides a process for the preparation of compounds of Formula I wherein R₁ is -CN, -OP, alkyl, aryl or heteroaryl; wherein P represents any suitable protecting group; and R₂ is alkyl or aryl; by reacting a compound of Formula II wherein R₁ is -CN, -OP, alkyl, aryl or heteroaryl; wherein P represents any suitable protecting group; and R₂ is alkyl or aryl; with a reducing agent (e.g. sodium borohydride) in the presence of a metal halid (e.g. CeCl₃) or a metal alkoxid (e.g. Ti(OiPr)₄).