An Efficient Asymmetric Synthesis of 2‐Substituted 1,4‐Benzodiazepin‐3‐one as a Potential Molecular Scaffold

Abstract 2‐Substituted 1,4‐benzodiazepine‐2‐one compounds ( 9 – 12 ) were obtained by a highly diastereoselective alkylation of a seven‐membered ring benzolactam ( 8 ) in the presence of ( R )‐phenylglycinol as a chiral inductor. The corresponding acid derivative ( 16 ) afforded a conformationally constrained structure suitable for preparing peptidomimetic analogues useful as a novel molecular scaffold. After cleavage of the chiral appendage this approach might also lead efficiently to enantiomerically pure 2‐substituted benzodiazepines ( 15 ). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)