3-甲基-2-环己烯-1-酮

tert-butyl 3-benzyl-2-methyl-4-oxocyclohex-2-enecarboxylate

tert-butyl 2-acetyl-5-oxohexanoate

2-methyl-4-oxo-cyclohex-2-enecarboxylic acid tert-butyl ester