Regiospecific oxidation of polycyclic aromatic phenols to quinones by hypervalent iodine reagents.

The hypervalent iodine reagents -iodoxybenzoic acid (IBX) and bis(trifluoro-acetoxy)iodobenzene (BTI) are shown to be general reagents for regio-controlled oxidation of polycyclic aromatic phenols (PAPs) to specific isomers (, , or remote) of polycyclic aromatic quinones (PAQs). The oxidations of a series of PAPs with IBX take place under mild conditions to furnish the corresponding -PAQs. In contrast, oxidations of the same series of PAPs with BTI exhibit variable regiospecificity, affording -PAQs where structurally feasible and -PAQs or remote PAQ isomers in other cases.

Synthesis of dibenzo[def,p]chrysene, its active metabolites, and their 13C-labeled analogues.

Dibenzo[def,p]chrysene (DBC) is a highly carcinogenic polycyclic aromatic hydrocarbon suspected to be involved in initiation of lung cancer in smokers. Efficient new syntheses of DBC, its active metabolites [DBC diol (1), DBC dione (2), DBC diol epoxide (3)], and their previously unknown 13C2-labeled analogues are reported. The 13C2-labeled analogues are required as standards for sensitive methods of analysis of their DNA adducts in human cells using stable isotope dilution liquid chromatography/tandem mass spectrometry.