Synthesis of Alkyl Thiochromano[2,3-c]pyrrole-9-carboxylate Derivatives Utilizing Benzo[b]thiofuran-2,3-dione, Maleimides, and Alkyl Alcohol/Water Mixtures

Abstract

AbstractA set of thiochromano[2,3-c]pyrrolidine-1,3-diones, incorporating α-hydroxy esters and their acids at the C-9 position, was prepared via direct interaction involving benzo[b]thiofuran-2,3-diones, maleimides, and alkyl alcohols in water at 90 °C. Structures of the new products were deduced from HRMS and NMR spectral data and confirmed by single-crystal X-ray crystallography. An insight into a proposed pathway involving a sequential Michael conjugate addition (initiated by the sulfur atom) and an aldol-type reaction is presented.