Strictly aminotelechelic oligopeptides with gamma -methylglutamate or gamma -benezylglutamate units were synthesized by oligomerization of the corresponding N-carboxyanhydride initiated by ethylenediamine. The degree of polymerization (DP) was controlled by the ratio of NCA to ethylenediamine concentrations for reaction times of less than 1 h and DP = 20. The aminotelechelic nature, which greatly depends on the conditions used during oligomerization, was confirmed by amino end-group quantification. Characterization was achieved by H-1 and C-13 NMR and IR spectroscopy. (C) 2001 Elsevier Science B.V. All rights reserved.