N-(3-oxobutanoyl)pyridine-4-carboxamide

3-乙酰基-4-羟基-6-甲基吡啶-2(1h)-酮

N-formyl-2,6-dimethyl-4-oxopyran-3-carboxamide

N-formylacetoacetamide

2,2-diethyl-6-methyl-1,3-dioxin-4-one