In the past, the a-ester y-chloride of carbobenzyloxyglutamic acid3-'[symbol: Z. GIU. OE~]~ or LC1 phthalylglutamic anhydrideg have been used in the synthesis of y-peptides. Both of these methods are open to objection since at some stage they involve the opening of an N- acylglutamic anhydride ring which may yield mixtures of a-and y-derivatives.'O In order to circumvent this difficulty, the y-hydrazide of carbobenzyloxy-L-glutamic acid,[ZGlu. OH (L)], ...
