Amino Acids and Peptides. XXIV. Phosphorus in Organic Synthesis. XIII. Application of Diphenyl Phosphorazidate (DPPA) to the Synthesis of the Protected N-Terminal Hexapeptide of Secretin

Abstract

The diphenyl phosphorazidate (DPPA) method, a new coupling procedure in the peptide synthesis, was successfully applied to the synthesis of Z-His(Z)-Ser-Asp(OBu^t)-Gly-Thr-Phe-OBu^t (I) corresponding to sequence 1-6 of secretin. Comparison of the DPPA method with the classical azide method was made by the fragment coupling of Ser-Asp with Gly-Thr-Phe, revealing that the former may be as good as the latter.