Chiral synthesis of indolizidines 209D and 167B via asymmetric oxidation of sulfides and sulfoxides

Chiral synthesis of indolizidine natural products (−)-209D and (−)-167B, as well as their antipodes, has been achieved through asymmetric oxidation of racemic thio-substituted indolizidines to the chiral sulfoxides and sulfones followed by Raney nickel reduction.