甲基7-(5-氧代-1-环戊烯-1-基)庚酸酯

乙基5-氧代-1-环戊烯-1-羧酸酯

ethyl 7-(2-oxocyclopent-3-en-1-yl)heptanoate

2-(6-乙氧羰基己基)环戊酮

ethyl 9-(5-oxocyclopenten-1-yl)nonanoate