TOPOGRAPHICALLY CONSTRAINED AROMATIC ALPHA-AZA-AMINO ACIDS - SYNTHESIS, MOLECULAR-STRUCTURE, AND CONFORMATION OF 2 AZATIC DERIVATIVES

3,4-Dihydro-2(1H)-phthalazinecarboxylic acid (azaTic) is a new conform ationally restricted analogue of phenylalanine which, due to its alpha -aza-nature, should allow, in addition to the topographical control ty pical of the Tic residue, a definite local perturbation of the backbon e conformation. Two aza Tic models, namely aza Tic-NH2 (2) and MeCO-az a Tic-NHMe (5), have been synthesized and their conformation has been determined and compared to that of the related Tic and azaPro models. (C) 1997 Elsevier Science Ltd. All rights reserved.