The simple synthesis of chiral polyazaoxacoronands derived from alpha-amino acids

Bisamidation of oxaloyl chloride using L-amino acid methyl ester hydrochlor ides afforded chiral diesters. The following reactions of diesters with 2,2 -(ethylene-dioxy)diethylamine, afforded tetramides possessing C-2 Symmetry. Coupling of N-hydroxysuccinimide ester of N-benzyloxycarbonyl-L-alanine wi th 1,5-diamino-3-oxapentane, followed by cleavage of protecting groups, aff orded an optically active diamine, which was transformed consequently into tetramide via the reaction with diglycolic acid dimethyl ester under high p ressure conditions.