Cycloadditions of olefins and acetylenes to dimethylketen: evidence for the (π2s+π2a) concerted mechanism
Abstract
The products and relative rates of cycloaddition of a series of olefins and acetylenes to dimethylketen have been examined. Steric and electronic factors are in accord with a concerted reaction in which the keten adds antarafacially, with differing degrees of bond formation, at the reaction termini in the transition state.