Mixed anhydrides in peptide synthesis. factors afffectlng urethane formation and racemization

Abstract

A comparative study on the effectiveness of two mixed anhydrides procedures in the synthesis of a series of hydrophobic tripeptides by using three solvents and four different hydrophobic nucleophiles has been carried out. Dicyclohexylcarbodiimide (DCC) method has also been used as reference for comparative purposes. The results show that despite the system Dpp/DMF provides the best chemical yields with these specific couplings, when retention of configuration is concerned the coupling method of choice should be DCC/HOBt using either THF or DMF as solvent system.