The chemistry of pyrrolic compounds. XXXV. Further observations on the chemistry of <i>Spirographis</i> porphyrin and its isomer: the oxidation offormylporphyrins

Evidence is presented which indicates that a mixture of hydriodic acid, acetic acid and air achieves the oxidation of formylporphyrins through the agency of peroxyacetic acid. The mechanism of the reaction is discussed. The oxidation of Spirographis porphyrin and its isomer are described and the product of these oxidations related to a methoxycarbonyldeuteroporphyrin of known structure. Improvements are recorded for the synthesis of Spirographis porphyrin and related compounds.