Histidine-derived hydrazide acetal monomers (3-dimethoxymethylbenzoyl)-l-histidine methyl ester 1 and (3-dimethoxymethylbenzoyl)-τ-benzyl-l-histidine methyl ester 2 were prepared from a histidine methyl ester and a τ-benzyl-histidine methyl ester by N-acylation with 3- (dimethoxymethyl) benzoic acid (3) followed by hydrazinolysis. Acid-promoted hydrolysis of each acetal hydrazide initially produced a library of cyclic oligomers that eventually ...
