Synthesis of (−)-Epibatidine and Its Derivatives from Chiral Allene-1,3-dicarboxylate Esters

Abstract

(−)-Epibatidine, an excellent candidate of non-opioidal anesthesia, was formally synthesized in short steps from di-(l)-menthyl (R)-allene-1,3-dicarboxylate that was facilely prepared as a single isomer by means of crystallization-induced asymmetric transformation from a diastereomer mixture of (R)- and (S)-allene-1,3-dicarboxylates. Taking advantage of the chiral synthesis, derivatives of (−)-epibatidine were also prepared for targeting diagnostic agents that could bind nicotinic acetylcholine receptors (nAChRs) in the mammalian central nerve system.