Transformation of Alkyl <i>N</i>-(Vinyloxy)benzimidates to Alkyloxazoles. Mechanism and Extension

Abstract

Abstract Transformation of alkyl N-(vinyloxy)benzimidates to alkyloxazoles proceeds through the intermediates: a charge-separated 1,2-oxazetidine derivative and then 1-hydroxy-2-[[methylthio(phenyl)methylene]imino]maleic acid diester, while their photochemical transformation takes place via a concerted [1,3] sigmatropic shift. As the extension of this reaction, the preparation of the precursor proposed for virginiamycin M2 synthesis and the reaction of N-analogs of alkyl N-(vinyloxy)benzimidates are described.