The cyclization of peptides and depsipeptides.

Constricting the peptide backbone into a more defined conformational form through cyclization is an activity evolved in nature and in synthetic work, the latter straddling only the most recent decades. The resulting conformational constraints increase the probability of an optimum response with bio-receptors. The purpose of this review is to highlight developments that have proved to be reasonably efficient in the macrocyclization of linear precursors into cyclic peptides and depsipeptides.