A novel approach to functionalized polycyclic systems; new aspects of the Diels–Alder reactions of 2-acyl derivative of 4H,6H-thieno[3,4-c]furan 5,5-dioxide

Abstract

The intramolecular Diels–Alder reaction of the 2-acyl derivative of 4H,6H-thieno[3,4-c]furan 5,5-dioxide 2a is achieved by the use of molecular sieves as additive to give the corresponding cycloadduct 4a in high yield. Addition of efeoophiles to this reaction media afforded the polycyclic compounds 5 and 7a–cvia tandem cycloaddition in a single step.