Unexpected dimerization of a tripeptide comprising a β,γ-diamino acid.

We have previously reported the synthesis of enantiopure β,γ-diamino acids and relevant short α/γ-peptide containing such building blocks. Complete nuclear magnetic resonance (NMR) studies, together with molecular modeling, highlighted the ability of a β,γ-diamino acid to induce various intramolecular turns. In this paper, we describe for the first time the formation of a dimeric structure constituted by α/γ/α-tripeptide and stabilized by intermolecular interactions. A structural model is proposed based on extensive NMR measurements.