4-(3,4-dichlorophenyl)-2-hydroxy-4-oxobutanoic acid

4-(2-硝基苯基)-4-氧代-2-羟基丁酸

3-methyl-5-hydroxy-imidazoline-2,4-dione

5-羟基-1-甲基咪唑啉-2,4-二酮

(E)-4-(4-hydroxyphenyl)-4-oxobut-2-enoic acid