Compounds with Bridgehead Nitrogen. 62 - NMR Spectra and Stereochemistry of Perhydropyridothiazepines and Related Systems

Article abstract of DOI:10.1002/mrc.1260280509

Perhydropyrido<1,2-c><1,3>thiazepine adopts (CDCl3 solution, 25 deg C) an equilibrium containing > 98percent trans-fused conformer, in contrast to perhydropyrido<1,2-c><1,3>oxazepine, which adopts a ca. 74percent trans fused <-> 26percent O-inside-cis-fused conformational equilibrium.The cis-(H-5a, H-8)-8-ethyl-substituted derivatives of both systems show increased preference for the S/O inside cis conformations.The related 2-tert-butylperhydropyrido<1,2-c><1,3>diazepine adopts predominantly the trans-fused conformation.