The spiropiperidine-3,3′-oxindole scaffold: a type II β-turn peptide isostere

An unprecedented chiral spiropiperidine oxindole system quaternary 3-aminooxindole and relying on a ring closing acts as an highly constrained Freidinger gamma-lactam, adopting assessed by modelling and spectroscopical studies. was synthesized starting from enantiopure metathesis as the key step. This compound a type II beta-turn conformation in solution, as (C) 2010 Elsevier Ltd. All rights reserved.