Syntheses of major and minor metabolites of benzo[c]chrysene

Benzo[c]chrysene (B[c]C), a weakly carcinogenic polycyclic aromatic hydrocarbon (PAH), has been detected in coal tar and crude oil. Its structure is intriguing in that it has a bay region and a fjord region in the same molecule. To study in vitro metabolism of B[c]C and to identify the metabolites of this compound, synthetic standards were needed. In this communication, we report the synthesis of B[c]C and its three proximate carcinogenic metabolites; namely, (±)-trans-1,2-dihydro-1,2-dihydroxyB[c]C (B[c]C-1,2-diol), (±)-trans-7,8-dihydro-7,8-dihydroxyB[c]C (B[c]C-7,8-diol), and (±)-trans-9, 10-dihydro-9,10-dihydroxyB[c]C (B[c]C-9,10-diol) from methoxy-substituted dinaphthylethylenes by photochemical cyclization. Major and minor phenolic metabolites of B[c]C were also synthesized.