N-benzhydryl-glycolamide esters (OBg esters) as carboxyl protecting groups in pept1de synthesis

Abstract N-Benzhydryl-glycolamide esters (OBg esters) of various N-protected amino acids have been synthesized. In order to demonstrate their usefulness in peptide chemistry, the syntheses of For-Met-Leu-Phe-OH (chemiotactic peptide) and Pro-Leu-Gly-NH 2 (MIF) have been carried out. OBg esters are compatible with commonly used protecting groups and are cleanly and selectively removed in mild alkaline conditions without any side reaction, except for β-benzyl aspartyl containing sequences.