Possible Intermediates in the Biosynthesis of Porphyrins

Abstract

Details of our synthesis of 5-aminomethyl-4,3′-dicarboxymethyl-3,4′-di-(2-carboxyethyl)-dipyrrylmethane (1b), as a stable potassium salt are now reported. This synthetic product had been shown to be an intermediate in the biosynthesis of uroporphinogen 1. The analogous tripyrrane, 15, should be available from the lactam of 2-(2-methoxycarbonylethyl)-3-methoxycarbonylmethyl-4,6-di-(2-ethoxycarbonylethyl)-5-ethoxy-carbonylmethyl-7-carboxymethyl-8-aminomethyl-tripyrrane (22) which has also been synthesized.5-Formyl-4,3′-di-ethoxycarbonylmethyl-3,4′-di-(2-ethoxycarbonylethyl)-5′-benzyloxycarbonyldipyrryl-methane (24), was obtained through the condensation of the bromomethyl pyrrole 2b with the hydrazone, 23, from a 2-formyl-5-free pyrrole and Girard's "T" reagent. This depends on the supression of the deactivating effect of the aldehyde group in a hydrazone from which the aldehyde is easily regenerated.