Stepwise Synthesis of γ‐Glutamic Acid 16‐Mer

γ‐Glutamic acid 16‐mer α‐ethyl ester was synthesized in stepwise transesterification of the ethyl ester group into benzyl ester group, followed by hydrogenation afforded γ‐glutamic acid 16‐mer with free carboxyl groups. Alkaline hydrolysis of γ‐glutamic acid 16‐mer α‐ethyl ester also afforded 16‐mer with free carboxyl groups. The two 16‐mers showed similar circular dichroism spectra. The structures and optical properties of γ‐glutamic acid dimer, trimer, tetramer, octamer, and 16‐mer were elucidated by ¹H NMR, ¹³C NMR, IR, circular dichroism spectra, and X‐ray. Specific rotation of the intermediates of 16‐mer increased as the number of the glutamate unit.