Competitive intramolecular [4+2] cycloaddition and [2+2] cycloaddition of sulfonylallene

Article abstract of DOI:10.1016/S0040-4039(00)79665-1

Thermal reaction of sulfonyl allenes proceeded by the intramolecular Diels-Alder ([4+2]) reaction and/or [2+2] cycloaddition reaction depending upon the substitution pattern, in which the effect is switching of the reaction pathway depending on a C(2) pos