3,4,5-三甲基吡咯-2-甲基乙酯

4-O-benzyl 2-O-ethyl 3-(3-ethoxy-3-oxopropyl)-5-methyl-1H-pyrrole-2,4-dicarboxylate

1-O-benzyl 6-O-ethyl 3-oxohexanedioate

5-ethoxycarbonyl-4-(3-ethoxy-3-oxopropyl)-2-methyl-1H-pyrrole-3-carboxylic acid