Enantio‐ and Diastereoselective Syntheses of 3‐Hydroxypiperidines through Iridium‐Catalyzed Allylic Substitution

Stereoselective syntheses of 3‐hydroxypiperidines have been developed. Key intermediates are N ‐protected allylamines that are prepared by an enantioselective iridium‐catalyzed allylic amination. A subsequent catch and release procedure that involves an epoxidation and base‐mediated elimination yields δ‐lactams that are suitably functionalized to prepare biologically active 3‐hydroxypiperidines. In addition, applications of this method to the total syntheses of deoxymannojirimycin, D ‐ erythro ‐sphingosine, and chiral building blocks of interest for medicinal chemistry are described.