ethyl 2,3-dimethyl-5-oxo-1,2-oxazole-4-carboxylate

2-acetyl-3-oxo-5-phenyl-valeric acid ethyl ester

ethyl 2,5-dihydro-2-methyl-5-oxo-3-(2-phenylethyl)-isoxazole-4-carboxylate

苄基丙酮

碳酸二乙酯