Chemistry of pyrrolic compounds. XXXVI. Some aspects of the chemistry of 2'-hydroxypropionate porphyrins: new syntheses of harderoporphyrin trimethyl ester, 'S-411 porphyrin' trimethyl ester and related compounds

The 2?-hydroxypropionate porphyrins (1h) and (2g) were obtained by sodium borohydride reduction of the corresponding keto esters. Dehydration of (1h) and (2g) led to the acrylate esters (1b) and (2b) respectively; fragmentation of both the hydroxyl and carboxyl functions in (1h) and (2g), by way of a cyclic intermediate, furnished the vinylporphyrins (1a) and (2a) respectively. The synthesis of the 2?- hydroxypropionate porphyrin (9a), a possible biogenetic precursor of protoporphyrin-IX, was achieved.