An expedient total synthesis of optically active piperidine and indolizidine alkaloids (-)-β-conhydrine and (-)-lentiginosine

Attempts directed toward the stereocontroled total synthesis of piperidine and indolizidine alkaloids resulted in the synthesis of (-)-beta-conhydrine 1 and (-)-lentiginosine 3. The synthesis of 1 and 3 were developed from protected D-mannitol as the chiral precursor, which involved nucleophilic addition and azide nucleophilic substitution, Barbier allylation, ring closing metathesis, and Sharpless asymmetric dihydroxylation as the key steps. (C) 2010 Elsevier Ltd. All rights reserved.