Enantioselective synthesis of nicotinic receptor probe 7,8-difluoro-1,2,3,4,5,6-hexahydro-1,5-methano-3-benzazocine

The development of a concise enantioselective synthesis of nicotinic alkaloid 1 is presented. The route features the synthesis and use of a stable aliphatic triflate 21 in an alkylation step to generate Heck precursor 24 and an enantioselective cyclization to establish a compound with the key [ 3.2.1]- bicyclic core, 29.