ethyl 5-oxo-2-phenyl-1,2-oxazole-4-carboxylate

diethyl 2-(2,2,2-trichloroethylidene)propanedioate

丙二酸二乙酯

原甲酸三乙酯

tetraethyl prop-1-ene-1,1,3,3-tetracarboxylate