4-oxononanedioic acid

ethyl 4-(6-methoxynaphthalen-2-yl)-4-oxobutanoate

ethyl 4-(diethylamino)-4-oxobutanoate

4-(4-甲氧基-2-甲基-苯基)-4-氧代-丁酸

ethyl 5-benzamido-4-oxopentanoate