Efficient Synthesis of Fmoc-Protected Azido Amino Acids

Abstract

The efficient two-step synthesis of Fmoc-protected l-azidoalanine and l-azidohomoalanine from readily available Fmoc-protected asparagine and glutamine, respectively, is reported. The synthetic route proceeds in good yield, requires no extra purification steps, and can be carried out on gram scale. The resulting azido amino acids are of sufficient purity for solid-phase peptide synthesis, as demonstrated in the synthesis of a model pentapeptide.