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

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