Enantioselective approach to functionalized quinolizidines: synthesis of (+)-julandine and (+)-cryptopleurine

Abstract

An efficient synthesis of functionalized quinolizidines was developed from an enantiomerically enriched γ-nitroketone, which is easily prepared by an organocatalytic ketone-nitroalkene Michael addition. Oxidative ring expansion of the nitroketone followed by reductive ring-opening leads to a suitably functionalized nitrodiol which is an intermediate to the title compounds.