Enantioselective synthesis of 11-hydroxy-(1′S,2′R)-dimethylheptyl-Δ8-THC, a very potent CB1 agonist

An enantioselective synthesis of the (1S,2R)-dimethylheptyl cannabinoid side chain has been developed and employed in the synthesis of 11-hydroxy-(1′S,2′R)-dimethylheptyl-Δ8-THC, one of the most potent traditional cannabinoids known. The synthesis involves a highly stereoselective addition of dimethylcopperlithium to an enoyl sultam which incorporates Opplozerʹs auxiliary.