Ring-opening reactions of methylenecyclopropanes with diphenyl diselenide upon heating; formation of 3-phenylselenyl-2,5-dihydrofuranderivatives

The reactions of methylenecyclopropanes 1 with diphenyl diselenide give ring-opened products 2 in good yields at 150 degreesC under nitrogen atmosphere for 3 h; the products 2 can further undergo oxidative cyclization with hydrogen peroxide to furnish 3-phenylselenyl-2,5-dihydrofurans 3 in moderate yields ( three steps) at room temperature in CH2Cl2 for 5 h; a plausible reaction mechanism has been proposed.