Synthesis of sequential polydepsipeptides involving depsipeptide formation by the 2-nitrophenylsulphenyl N-carboxy α-amino acid anhydride (Nps–NCA) method

Abstract

Sequential polydepsipeptides containing a tripeptide sequence Ala-Ala-Glu(OEt) and various α-hydroxy acids have been successfully prepared by polycondensation of tetradepsipeptide pentachlorophenyl esters. The latter were synthesized by preparation of didepsipeptide free acids by the Nps-NCA method followed by active esterification and peptide chain elongation by the so-called ‘back-up’ procedure.