Total synthesis of the porphyrin mineral abelsonite and related petroporphyrins with five-membered exocyclic rings

A reliable synthesis of porphyrins with five-membered exocyclic rings from b-bilenes has been developed. This methodology has been applied to the first total synthesis of the porphyrin mineral abelsonite, as well as the widespread petroporphyrin deoxophylloerythroetioporphyrin (DPEP) and its 3-desethyl analogue.