ethyl 5-methyl-2-oxo-1,3-dihydropyrrole-4-carboxylate

ethyl 2-(5,7-dihydroxy-4-methyl-2-oxochromen-3-yl)acetate

4-(3-甲氧基苯基)-4-氧代丁酸

琥珀酸

2-丁基-1,4-二氢-6-甲基-4-氧代-5-嘧啶乙酸乙酯