MIXED ANHYDRIDES IN PEPTIDE SYNTHESIS. INFLUENCE OF THE SOLVENT AND THE AMINE ON THE RACEMIZATION OF DMet RESIDUE OF AN ENKEPHALIN SEQUENCE.

Article abstract of DOI:10.1016/S0040-4020(01)81686-0

A comparative study on the effectiveness of all possible amine/solvent combination with three different solvents (THF, DCM, DMF) and three different bases (NMM, NMPi, NMPo) in avoiding the racemization of the DMet residue during a mixed anhydride coupling has been carried out.The results show that the best combination is THF/NMM.Though, when more polar solvents are required, the system DMF/NMPo is recommended.