4-羟基丁酸甲酯

2,5-二羟基-4-甲基-2,5-二氧代-3-呋喃丙酸

1-O-ethyl 2-O,4-O-dimethyl 1-methylbut-1-ene-1,2,4-tricarboxylate

6-chloroquinoline-2,4-dicarboxylic acid

5-氧代四氢呋喃-2-羧酸甲酯