A Practical Approach to the Synthesis of 2,4-Disubstituted Oxazoles from Amino Acids

Abstract

[reaction: see text] A new sequence for the synthesis of various 2,4-disubstituted oxazoles from alpha-amino acids is reported. The method is shown to be general and incorporates the reagent combination, triphenylphosphine/hexachloroethane, for cyclodehydration of intermediate alpha-acylamino aldehydes. Implementation of this reagent system for the conversion of alpha-acylamino ketones to oxazoles is briefly investigated.