5-(Formylmethyl)-3-methyl-3-(phenylthio)dihydrofuran-2-one 、
Diethyl (2-oxo-3,3a,4,8b-tetrahydro-2H-indeno<1,2-b>furan-3-yl)phosphonate 在
sodium hydride 作用下,
生成 3-<2-(4-Methyl-5-oxo-4-(phenylthio)tetrahydrofuran-2-yl)ethylidene>-3,3a,4,8b-tetrahydroindeno<1,2-b>furan-2-one