4-羟基-4-甲基-6-氧代-2-苯基-1,3-环已二酸二乙酯

2,4-二甲基吡咯-3,5-二羧酸二乙酯

1,6-二甲基-3-乙酰基-4-羟基吡啶-2(1H)-酮

1,4-dimethyl-6-(N-methylcarbamoylmethyl)-pyridin-2-one

4-hydroxy-1,6,7-trimethyl-1,6-naphthyridine-2,5-dione