1,3-Oxathiolan-5-ones are a hitherto very poorly studied class of sulfur heterocycles some of which have been shown to be important precursors for HIV drugs or bioactive, anticarcinogenic compounds. We have developed a novel and effective process for the direct generation of this structural motif in a (3+2)-cycloaddition of thioketones and acetylenedicarboxylic acid. The cycloadducts were obtained with complete regioselectivity and up to >99 % yield. The heterocyclic motif was confirmed by X-ray diffraction analysis.

Abstract

Herein, we report a novel protocol for the direct synthesis of 1,3-oxathiolan-5-ones based on the (3+2)-cycloaddition between thioketones and acetylenedicarboxylic acid. The products were obtained in a one-pot reaction within short reaction times and in typically very good yields. The product structure was confirmed by X-ray diffraction analysis.