The pseudopentapeptide cyclo(-Arg(1)-Gly(2)-Asp(3)-D-Phe(4) psi[CH2NH]Val(5)-) (1) was synthesized by a combination of solution and solid-phase methods. The reduced peptide bond was incorporated as a dipeptide building block, a versatile synthetic alternative that avoids the reduction of imine intermediates. NMR spectroscopy was used to investigate the structure of the peptide. Interproton distances from a NOESY spectrum served as restraints in a molecular dynamics simulation. Though the peptide exhibits a typical beta II’,gamma conformation with the D-Phe in the i + 1 position of a gamma turn, this solution conformation is different from that of the parent peptide cyclo(-Arg(1)-Gly(2)-Asp(3)-D-Phe(4)-Val(5)-) with the D-Phe in the i + 1 position of beta II’. The influence of the reduced peptide bond is examined by computational methods. The psi[CH2-NH] bond proved to be a strong hydrogen bond donor and thus rigidifies the peptide backbone.