Two isomeric phenolic derivatives of trans-7,8-dihydro-7,8-dihydroxybenzo(a)pyrene (42), 3,7,8-trihydroxy-trans-7,8-dihydrobenzo(a)pyrene (40), and 1,7,8-trihydroxy-trans-7,8-dihydrobenzo(a)pyrene (41), have been prepared in order to probe their relevance in the carcinogenesis of benzo(a)pyrene. Two methods have been developed for the synthesis of the key intermediates 3-acetoxy-9,10-dihydrobenzo(a)pyrene (25) and 1-acetoxy-9,10-dihydrobenzo(a)pyrene (26). In one method, known 1-methoxypyrene-6-carboxaldehyde (5) and 1-methoxypyrene-8-carboxaldehyde (6) were homologated, and the resulting 4-(methoxypyrene)butanoic acids 14 and 18 were cyclized with polyphosphoric acid (PPA) at 105{degree}C to produce 3-methoxy- and 1-methoxy-7,8,9,10-tetrahydrobenzo(a)pyren-7-one (19 and 21, respectively). The PPA cyclization at low temperature (90{degree}C) produced primarily the undesired seven-membered ring ketones 23 and 24, respectively. Demethylation of methoxy ketones 19 and 21 followed by successive reduction, dehydration, and acetylation afforded the key intermediates 25 and 26. The second method involves bromination of the trimethylsilyl cyanide derivative 27 of 7,8,9,10-tetrahydrobenzo(a)pyren-7-one followed by removal of the protecting group. 1-Bromo-7,8,9,10-tetrahydrobenzo(a)pyren-7-one (28) was obtained as a major and 3-bromo-7,8,9,10-tetrahydrobenzo(a)pyren-7-one (29) as a minor products of this synthesis.