HOBt·DCHA-Mediated Synthesis of Sterically Hindered Peptides employing Fmoc-Amino Acid Chlorides in Both Solution-Phase and Solid Phase Methods

Abstract

The synthesis of peptides employing Fmoc-amino acid chlorides in presence of HOBtÁDCHA salt in solution as well as by the solid-phase methods is described. The coupling was found to be complete in 30 min and free from racemization. The synthesis of b-casomorphin by solid-phase protocol employing Fmoc-amino acid chloride=HOBtÁDCHA in DMF-CH 2 Cl 2 has also been outlined. The final peptide was obtained in 80% yield and was fully characterized.