The tripeptide N-Cbz-βGly-Gly-Gly-Obz

The title peptide, N-benzyl-oxycarbonyl-β-glycylglycylglycine benzyl ester, C22H25N3O6, contains a non-proteinogenic amino acid residue, β-glycine, which is a homologated analogue of glycine. In the mol-ecular structure, β-glycine adopts an extended conformation with a trans conformation about its C(β)-C(α) bond. The second glycine residue adopts an extended conformation while the third glycine residue adopts a helical conformation. In the crystal, three N-H⋯O hydrogen bonds, two involving the same carbonyl O atom as acceptor, results in an infinite two-dimensional network parallel to the bc plane.