dibenzyl 3-ethoxycarbonylmethyl-4'-methoxycarbonylmethyl-4,3'-dimethylpyrromethane-5,5'-dicarboxylate

dibenzyl 2,7-bisethoxycarbonylmethyl-5-phenyl-3,8-dimethyldipyrrylmethane-1,9-dicarboxylate

3,3'-(3,7,12,17-tetramethyl-1,19-dioxo-8,13-divinyl-1,19,22,24-tetrahydro-21H-biline-2,18-diyl)-bis-propionic acid dimethyl ester