Reactions of Monoaryl-Substituted Methylenecyclobutanes and Methylenecyclopropanes with 1-Hydroxybenzotriazole (HOBt), 1-Hydroxy-7-azabenzotriazole (HOAt), and 1-Hydroxysuccinimide (HOSu)

Monoaryl-substituted methylenecyclobutanes (MCBs) and methylenecyclopropanes (MCPs) react with 1-hydroxybenzotriazole (HOBt), 1-hydroxy-7-azabenzotriazole (HOAt), and 1-hydroxysuccinimide (HOSu) smoothly to produce the corresponding cyclobutylmethanone and cyclopropylmethanone derivatives 2, 4, and 5 via a cascade epoxidation and nucleophilic addition process or the corresponding epoxides 6 in moderate to good yields under mild conditions. A plausible mechanism has been proposed on the basis of the control experiments and the isolation of the reaction intermediates.