“…This sequence has been employed extensively in the authors laboratory to synthesize the isomeric phenol derivatives of benz[a]anthracene, benzo [a] pyrene, 7,12-dimethylbenz[a]anthracene, and other polycyclic arenes.33 '149'157•159 The phenols are among the principal metabolites of the carcinogenic hydrocarbons,164 and the phenolic derivatives of authentic structures are required for identification of the individual isomers produced. 165 Reactions of hydroaromatic compounds with DDQ in methanol afford principally the oxidation products arising through reaction of the intermediate carbonium ions with the solvent. Reaction of 8,9,10,11-tetrahydrobenz[a]anthracene (30) with 2 equiv of veniently synthesized from the cyclic ketones, if the latter are converted to the related enol acetates before treatment with DDQ in methanol furnished the related ketones 31 and 32 in 4:1 32 och3 34 ratio as the major products; minor amounts of the related phenol methyl ethers 33 and 34 were also produced.33 Similar reaction of 7-methylbenz[a]anthracene afforded 7-formylbenz[a]anthracene (35).157 D. Stepwise Dehydrogenation and Theoretical Prediction of Product Structure Partial dehydrogenation of hydroaromatic molecules in stepwise fashion (removing one pair of hydrogen atoms at a time) holds promise as a method of important synthetic utility.…”