2,2-dimethyl-5-acetyl-3(2H)-furanone 、 2-<(triphenylphosphonium)methyl>-7H-furo<3.2-g><1>benzopyran-7-one chloride 在
potassium tert-butylate 作用下,
生成 (Z)-<2-(4,5-dihydro-5,5-dimethyl-4-oxo-2-furanyl)propenyl>-7H-furo<3.2-g><1>benzopyran-7-one 、 (E)-<2-(4,5-dihydro-5,5-dimethyl-4-oxo-2-furanyl)propenyl>-7H-furo<3.2-g><1>benzopyran-7-one