A Concise and Diastereoselective Synthesis of Piperidine and Indolizidine Alkaloids via Aza-Prins Cyclization

The synthesis of 2-substituted and 2,4-disubstituted piperidine alkaloids such as (+/-)-coniine, (+/-)-hydroxypipecolic acid, (+/-)-pipecolic acid, (+/-)-coniceine, and (+/-)-4-hydroxy-2-hydroxy-methyl piperidine have been accomplished in a highly diastereoselective manner by employing aza-Prins cyclization as a key step to construct the piperidine core of these alkaloids.