Enantioselective synthesis of the carbocyclic nucleoside (-)-abacavir.

An enantiopure beta-lactam with a suitably disposed electron withdrawing group on nitrogen, participated in a pi-allylpalladium mediated reaction with 2,6-dichloropurine tetrabutylammonium salt to afford an advanced cis-1,4-substituted cyclopentenoid with both high regio- and stereoselectivity. This advanced intermediate was successfully manipulated to the total synthesis of (-)-Abacavir.