Thermal rearrangement of aryl(chloro)methylenetetrahydrofuran-2,4,5-triones: its mechanism and the chemistry of the resulting aroylchloro-maleic anhydrides

Abstract

On heating above the m.p., aryl(chloro)methylenetetrahydrofuran-2,4,5-triones rearrange with double bond shift and carbonyl oxygen–chlorine interchange giving aroylchloromaleic anhydrides. ¹⁴C Labelling studies and other work show the integrity of the carbon framework, and a mechanism involving formation of an oxet is proposed: this links mechanistically the formation and the rearrangement of the triones. Aspects of the chemistry of aroylchloromaleic anhydrides are reported.