The Use of N-Hydroxy-5-norbornene-2, 3-dicarboximide Active Esters in Peptide Synthesis

Abstract

N-Hydroxy-5-norbornene-2, 3-dicarboximide (HONB) was found to be an excellent reagent to be used in couple with N, N'-dicyclohexylcarbodiimide (DCC) for the peptide synthesis. Various racemization tests by the use of this reagent were conducted to see the degree of racemization during the peptide synthesis. The newly employed reagent (HONB) decreases racemization, prohibits formation of N-acylurea and affords peptides in excellent yields and a high state of purity. To evaluate this new reagent, luteinizing hormone releasing hormone (LH-RH) was prepared by the new active ester method.