3-(2-oxocyclopentyl)propanal

头孢匹罗

1,5,6,7-四氢-4-羟基-2H-环戊并[b]吡啶-2-酮

2-氨基-1-环戊烯甲酸乙酯

3-Carbethoxy-1-pyrindan-2,4-dion