ethyl 2-methyl-6-oxoheptanoate

1-(1,2-dimethylcyclopent-2-en-1-yl)ethanone

ethyl 3-methyl-2-oxocyclopentane-1-carboxylate

1-(1-methylcyclopent-2-en-1-yl)ethanone

1-甲基-2-亚甲基环戊烷e羰基氯化物