3-carboxymethyl-3-hydroxy-glutaric acid

草酸二乙酯

丙酮

ethyl 3-amino-3-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)propanoate

1,1,5,5-tetrachloropenta-1,4-dien-3-one