Interplay of structure and reactivity in a most unusual furan Diels-Alder reaction

A study uses density functional theory (DFT) calculations to study the Diels-Alder reactions of difluorinated alkenoate ethyl 3,3-difluoro-2-(N,N-diethylcarbamoyloxy)-2-propenoate with furan and a range of substituted furans in the presence of a tin(IV) catalyst. Results reveal a highly polar transition state, which is stabilized by the Lewis acid catalyst Sn[Cl.sub.4] and by polar solvents.