Diastereoselective spirocyclopropanation of (E)-2-ylidene-3-cyclohexenones and sulfur ylides

Abstract

A diastereoselective spirocyclopropanation reaction of (E)-2-ylidene-3-cyclohexenones and stabilized sulfur ylides is reported. This [2 + 1] annulation reaction enables rapid and efficient assembly of a series of spirocyclopropyl 3-cyclohexenones in fair to excellent yields and with high to excellent diastereoselectivity. The utility of this methodology is further showcased by a gram-scale reaction, as well as the construction of 2H-chromene, dihydrobenzofuran and chroman derivatives through readily operable cyclopropane ring-opening/cyclization reactions.