methylamino-5 oxo-3 hexene-4 N-methylamide

1-乙基-4-羟基-6-甲基吡啶-2(1H)-酮

6-methyl-4-phenylmethoxypyran-2-one

ethyl 2,4-dihydroxy-6-(2-oxopropyl)benzoate

4-hydroxy-3-[(4-hydroxy-6-methyl-2-oxo-1H-pyridin-3-yl)-phenylmethyl]-6-methyl-1H-pyridin-2-one