From amino acids to fused chiral pyrrolidines and piperidines via the INOC route

Intramolecular nitrile oxide olefin cycloaddition (INOC) reactions of oximes 1-3 and of 24-27 derived from 1-amino acids have been found to proceed stereoselectively, yielding tricyclic fused pyrrolidines and piperidines. Further manipulation led to chiral hydroxymethyl-substituted fused piperidines 33-35 and to 3-amino-4-(1-hydroxypropyl)-2-mercaptomethyl-N- methylpiperidine (36). The structures and stereochemistries of the fused systems, as well as those of the piperidines, have been established by NMR.