ANOMALOUS DOUBLE CYCLIZATION REACTIONS OF BETA-FORMYLPORPHYRINS

Treatment of nickel(II) and copper(II) complexes of 2(beta)-formyl-mes o-tetraphenylporphyrins with strong acid results in intramolecular cyc lization involving the carbonyl carbon and the ortho-phenyl position l eading to naphthoporphyrin derivatives. However, when electron-releasi ng groups are present at the m-phenyl positions, a second cyclization occurs involving the 3(beta) position and the ortho position of the ad jacent phenyl ring to give an additional fused ring.