An approach towards the total synthesis of (+)-epiquinamide and (+)-α-conhydrine from Garner aldehyde

A short and stereoselective route for the synthesis of 1-hydroxyquinolizidine, an advanced synthetic intermediate for the total synthesis of (+)-epiquinamide is presented. The key synthetic steps involve diastereoselective nucleophilic addition on L-serine derived Garner aldehyde and acid mediated (nSA) ring closing metathesis. The methodology is also elaborated successfully for the total synthesis of (+)-alpha-conhydrine, an important piperidine alkaloid. (C) 2009 Elsevier Ltd. All rights reserved.