Synthesis and Antifungal Activity Evaluation of 3-Hetaryl-2,5-dihydrofuran-2-ones. An Unusual Fragmentation of the Oxazole Ring via 2,3-Selenoxide Shift

Abstract

In continuing the studies on the synthesis and evaluation of antifungal activity of the analogues of (-)incrustoporine, the replacement of the phenyl moiety at C3 of the furanone ring with a hetaryl substituent was considered. Thus, a series of 5-alkyl-3-hetaryl-2,5-dihydrofuran-2-ones with the thienyl, furyl and thiazolyl moieties attached to C3 was synthesized, and the compounds subjected to antifungal activity screening. In the preparation of compounds containing the oxazolyl fragment, the [2,3]-sigmatropic rearrangement led to the fragmentation of the oxazole ring, resulting in the formation of 3-(1-benzamido-2-oxoethylidene)-5-methyltetrahydrofuran-2-one. Somewhat surprisingly, the antifungal efficiency of the derivatives was lower in comparison with analogues containing a substituted phenyl at C3.