(2,3-dihydro-5-ethoxy-4-ethoxycarbonyl-2-oxofuran-3-ylidene)triethoxyphosphorane

2,2,2-triethoxy-3,4-bis(ethoxycarbonyl)-1,2-oxaphospholan-5-one

亚磷酸三乙酯

富马酸二乙酯