An Access to Aza-Freidinger Lactams and <i>E</i>‑Locked Analogs

Abstract

Freidinger lactams, possessing a peptide bond configuration locked to <i>Z</i>, are important key elements of conformationally restricted peptidomimetics. In the present work, the C_αH_<i>i+</i>1 unit has been replaced by N, leading to novel aza-Freidinger lactams. A synthesis to corresponding building blocks and their <i>E</i>-locked analogs is introduced. The versatile buildings blocks reported here are expected to serve as useful elements in peptide synthesis