Regiospecific Preparation of a Suitably Protected β-Branched Aspartic Acid Dipeptide

Abstract

A new efficient synthetic approach for the preparation of Nα-protected β-L-aspartyl-L-aspartic acid dipeptide was elaborated. The distinctive features of the developed approach include utilization of readily available starting materials (Cbz-asparagine and dimethyl aspartate), aspartimide formation suppression employing electrostatic effect in a final deprotection step and an employment of a novel reagent (NaNO2/aqueous trifluoroacetic acid) for transformation of protected asparagine derivative into the corresponding aspartic acid. The developed method allowes preparation of aspartic acid derivatives that find application in carbohydrate polivalent interaction studies as well as in preparation of microbicidal dendrimeric constructs.