Rearrangements during the synthesis of substituted 1-benzylpyrrolidines and 3-substituted 1-benzylpiperidines

The preparation and interconversion of some 2-substituted 1-benzypyrrolidines and 3-substituted 1-benzyl-piperidines through intermediate aziridines is described. Reduction of a mixture of 2-azidomethyl-1-benzyl-pyrrolidine and 3-azido-1-benzylpiperidine, prepared either from 2-chloromethyl-1-benzylpyrrolidine or 3-chloro-1-benzylpiperidine, afforded a 50 : 50 mixture of 2-aminomethyl-1-benzylpyrrolidine and 3-amino-1-benzyl-piperidine.