Modified Carbobenzyloxy Groups in Peptide Synthesis

Abstract

THE ‘carbobenzyloxy’ method of peptide synthesis¹ has proved its value in many important syntheses. Nevertheless, the practical difficulties still encountered in this field suggest that improved protecting groups should still be sought. We have recently been examining benzyl chloroformates substituted in the benzene ring, and other closely related compounds, in the hope that the amino-acid and peptide derivatives might crystallize more readily and that other properties, such as stability and ease of removal of the protecting group, might differ in such a way as to increase the scope of this method of synthesis.