Studies on the synthesis of (-)-11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC) and related compounds: An improved oxidative procedure

Article abstract of DOI:10.1055/s-1991-26590

A facile procedure is described whereby Δ⁹-THC aldehydes 4, as their tert-butyldimethylsilyl derivatives, are conveniently oxidized to the corresponding acids with sodium chlorite in the presence of a large excess of 2-methyl-2-butene without isomerization of the Δ⁹-double bond. Deprotection of the O-protecting group with tetrabutylammonium fluoride in tetrahydrofuran gave the acids 2 in an overall yield of ≥80%. A study of other oxidizing agents and protecting groups demonstrated that this is the procedure of choice for the preparation of 9-carboxy-Δ⁹-tetrahydrocannabinols.