Patent ID: 6291684
Filing Date: 2001-09-18
Classification: C07D

Abstract:
A process for preparing a compound of structure VI ##STR22##wherein:R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 are selected from the group H or alkyl and when R.sub.1 and R.sub.2 are alkyl can be joined to form a cycloalkyl;R.sub.6 is selected from the group consisting of H, alkyl, substituted alkyl, aryl, substituted aryl, cycloalkyl, or heterocyclo;R.sub.7 is selected from the group consisting of alkyl, substituted alkyl, aryl, or substituted aryl; andP.sub.1 is selected from the group H, alkyl, substituted alkyl, alkanoyl, substituted alkanoyl, aroyl, substituted aroyl, trialkylsilyl, aryl dialkylsilyl, diaryl alkylsilyl, triarylsilyl;which comprises:(a) reacting a compound of structure I ##STR23##wherein R.sub.1-6 and P.sub.1 are defined as above with at least one metal halide salt to form structure II; ##STR24##(b) reacting the product of (a) with at least one azide salt to form structure III; ##STR25##(c) conducting a Mitsunobu reaction with the product of (b) wherein R.sub.7 is defined as above to form the structure IV; ##STR26##(d) cleaving the ester group of the product of (c) to form structure V; ##STR27##and(e) reducing and cyclizing the product of (d) with a reducing agent to form the stereospecific form of structure VI.