Synthesis and structures of methyl-substituted 1,2,4,5-tetrahydro-3H-spiro(benz-2-azepine-3,4′-piperidines)

Methyl-substituted 1,2,4,5-tetrahydro-3H-spiro(benz-2-azepine-3,4′-piperidines) were obtained by the intramolecular cyclization of 4-allyl-4-N-benzyl(α-phenylethyl)aminopiperidines in an acidic medium. The individual isomers of 1′-benzyl-2′,5,5′-trimethyl-1,2,4,5-tetrahydro-3H-spiro(benz-2-azepine-3,4′-piperidine) were isolated, and their structures were established. © 1992 Plenum Publishing Corporation.