Synthesis of 5-R-3-diphenylmethylene-2,3-dihydro-2-furanones from 5-substituted 2,3-dihydro-2,3-furandiones and phenylbenzoyldiazomethane

3-Reactions of 5-aryl, 5-heteryl, and 5-styryl-2,3-dihydro-2,3-furandiones with phenylbenzoyldiazomethane gave rise to 5-substituted 3-dipenylmethylene-2,3-dihydro2-furanones. The possible intermediates and reaction products were investigated by semiempirical SCF MO LCAO method in AM1 approximation.