4-丁基-3,5-二甲基-1H-吡咯-2-羧酸乙酯

ethyl 5-ethoxy-2-methyl-1,3-oxazole-4-carboxylate

ethyl N-[(benzyloxy)carbonyl]glycyl-O-ethyl-3-oxoserinate

3,4-二乙基-5-甲基-2-吡咯羧酸乙酯

4,5-diethyl-3-methyl-pyrrole-2-carboxylic acid ethyl ester