(2R,2(1)S)-8-Ethenyl-2(1),2(2)-bis(methoxycarbonyl)-17-(3-methoxy-3-oxopropyl)-2,7,12,18-tetramethyl-2,2(1)-dihydrobenzo[b]porphyrin-13-propanoic acid is the 2(1),2(2),17-trimethyl ester of (2R,2(1)S)-2(1),2(2)-dicarboxy-8-ethenyl-2,7,12,18-tetramethyl-2,2(1)-dihydrobenzo[b]porphyrin-13,17-dipropanoic acid. It is a beta-substituted porphyrin, a carboxylic acid, and a methyl ester. It is functionally related to (2R,2(1)S)-2(1),2(2)-dicarboxy-8-ethenyl-2,7,12,18-tetramethyl-2,2(1)-dihydrobenzo[b]porphyrin-13,17-dipropanoic acid and an enantiomer of (2S,2(1)R)-8-ethenyl-2(1),2(2)-bis(methoxycarbonyl)-17-(3-methoxy-3-oxopropyl)-2,7,12,18-tetramethyl-2,2(1)-dihydrobenzo[b]porphyrin-13-propanoic acid.