2-甲基-5-氧代-2-吡咯烷甲腈

3-(4-methyl-2,5-dioxo-imidazolidin-4-yl)-propionic acid

乙酰丙酸

Dimethyl (E)-2-(benzylideneamino)-2-methylpent-3-ene-2,5-dioate

2-acetyl-4-cyano-2-methyl-butyric acid ethyl ester