Synthesis and Evaluation of the β‐Turn Properties of 4‐Amino‐1,2,4,5‐tetrahydro‐2‐benzazepin‐3‐ones and of Their Spirocyclic Derivative

Abstract

Abstract A series of 4‐amino‐tetrahydro‐2‐benzazepin‐3‐one derivatives (Ac–Aba–Xxx–NHMe) were prepared as tetrapeptide mimetics. Considering the structural resemblance with the so‐called Freidinger lactams, their propensity to adopt a β‐turn conformation was investigated by NMR spectroscopy (solvent and temperature dependence) and molecular modeling. Interestingly, most of these lactams adopt extended conformations, only the spiro‐benzazepinone 9 has a strong preference for the formation of a β‐turn. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)