A Convenient and Facile Synthesis of Naturally Occurring 2,5-Diaryloxazoles

Abstract

A facile and high yielding synthesis of naturally occurring 2,5-diaryloxazoles including annuloline, balsoxin, texamine and texaline, has been reported. The protocol involves initial reaction of [hydroxy(tosyloxy)iodo] benzene with enolizable ketones to prepare α-tosyloxy ketones, which upon treatment with HMTA and followed by hydrolysis in presence of hydrochloric acid led to α-amino ketones in fairly good yields. Acylation of α-amino ketones produced α-acylamino ketones which upon cyclodehydration in presence of triphenylphosphine and iodine led to 2,5-diaryloxazoles in very good yields .