Transformation of a monovinylporphyrin to benzoporphyrins via Diels-Alder adducts

Article abstract of DOI:10.1016/S0040-4039(01)93324-6

A β-unsubstituted-β'-vinylporphyrin has been synthesized which reacted with an excess of acetylenedicarboxylate ester to give monobenzoporphyrins in high yield. Evidence that suggests an isomerization of the initial adduct to a new porphyrin enroute to the benzoporphyrin is presented.