Synthesis and nicotinic receptor activity of a hydroxylated tropane

(±)-3α-Hydroxy homoepibatidine 4 has been synthesized from the alkaloid scopolamine 5 and its properties as a nicotinic agonist assessed. While still binding strongly, the compound showed reduced agonist potency for the α4β2 nAChR compared with the parent compound epibatidine 1. Compound 4 also displayed generally similar binding and selectivity profiles at α4β2, α2β4, α3β4, and α4β4 nAChR subtypes to those for nicotine.