Two metabolites of cannabinol (1-hydroxy-6,6,9-trimethyl-3-pentyl-6H-dibenzo[b,d]pyran) in man, 11-hydroxycannabinol (8) and 1-hydroxy-6,6-dimethyl-3-pentyl-6H-dibenzo[b,d]pyran-9-carboxyli acid (7), have been totally synthesized together with three possible metabolites, 11-oxocannabinol (9), 8-hydroxycannabinol (15), and 10-hydroxycannabinol (21). This is the first total synthesis of the novel compound (21) and the previously isolated acid (7) and occurs in high yield; compounds (8), (9), and (15) were obtained in substantially higher yields than had been achieved by partial synthesis only. The key step in these syntheses was the regiospecific formation of the aryl–aryl bond via nucleophilic aromatic substitution of the methoxy group in the o-methoxyaryldihydro-oxazoles (2), (11), and (17) by the Grignard reagent, 2,6-dimethoxy-4-pentylphenylmagnesium bromide. The acid (7) was prepared from the new and possibly psychoactive 9-bromo-9-norcannabinol (6), which was obtained from 4-bromo-2-methoxybenzoic acid. Reduction of the acid (7) with lithium aluminium hydride gave 11-hydroxycannabinol, which was oxidized by Jones reagent to 11-oxocannabinol. 8- and 10-Hydroxycannabinol were synthesized in several steps from 2,5-dimethoxy-p-toluic acid and 2,3-dimethoxy-p-toluic acid, respectively.