Abstract
The use of backbone conformational constraints has acquired increasing importance in the design and synthesis of structurally restricted agonists and antagonists of bioactive peptides. Here I discuss the preferred conformations of four among the most popular types of such peptide surrogates: (a) Peptides from Cα,α‐dialkylated residues, (b) tetrazolyl peptides, (c) (γ‐ and δ‐) lactam‐containing peptides, and (d) thiated peptides. Emphasis is given to conformational energy computations and x‐ray diffraction analyses of selected model compounds and analogues of small bioactive peptides such as the formylmethionyl tripeptide chemoattractant and MIF.