Synthesis of 2-Hydroxybenzo[a]pyrene, a Tumorigenic Phenol Derivative of Benzo[a]pyrene

Abstract An efficient synthesis of 2-hydroxybenzo[a]pyrene (1a) from 4,5,9,10-tetrahydropyrene via 2-methoxy-4,5,9,10-tetrahydropyrene (2e) is described. Friedel–Crafts acetylation of tetrahydropyrene affords the 2-acetyl derivative which is transformed to the 2-methoxy derivative 2e via Baeyer–Villager oxidation, hydrolysis, and treatment with dimethyl sulfate. Friedel–Crafts succinoylation of 2e with succinic anhydride and AlCl3 takes place regiospecifically in the 7-position. The product is transformed to 1a via Clemmensen reduction, HF cyclization, Wolff–Kishner reduction, catalytic dehydrogenation, and demethylation with HBr.