hept-5-enoic acid

2-ethyl-2-cyclopent-1-enyl-cyclopentanone

四氢-5-氧代-2-呋喃羧酸

3,3a,4,5,6,6a-hexahydrocyclopenta[b]furan-2-one

4a,9a-dimethoxy-dodecahydro-dibenzo[1,4]dioxine