A simple synthesis of chiral macrocyclic tetraamides derived from α-amino acids

Bisamidation of oxalyl chloride using four L-alpha-amino acid esters afforded chiral diesters which were reacted with three alpha,omega-diainines under high-pressure conditions (10 kbar) to give macrocyclic tetramides of C-2-symmetry. (C) 2002 Published by Elsevier Science Ltd.