Abstract
Δ1-Tetrahydrocannabinol (Δ1-THC, Ia) was oxidized with selenium dioxide to yield 7-hydroxy-(VI), 6α-hydroxy-(VIIa), 6β-hydroxy-(VIIIa) and 6-oxo-Δ1-THC (IX) together with cannabinol (CBN, III), 7-hydroxy-(X), 6-hydroxy-(XI) and 7-oxo-CBN (XII). Δ6-THC (IIa) was transformed merely to 7-hydroxy-(IVa) and 7-oxo-Δ6-THC (Va) in a similar manner. Individual products isolated are well defined mainly on the spectroscopic evidences. The oxidation of Ia favors the endocyclic allyl methylene rather than the exocyclic allyl methyl while the reverse is the case with IIa. Such a sharp contrast shown in their reactivities as mentioned above must be interpreted in terms of the steric interference at the reactive center.
