Synthesis and utility of β-selenol-phenylalanine for native chemical ligation-deselenization chemistry.

An efficient synthetic route to a suitably protected β-selenol-phenylalanine derivative from commercially available Garner's aldehyde is described. The incorporation of this building block into peptides and its application in native chemical ligation reactions with peptide thioesters are demonstrated. Ligation products were chemoselectively deselenized (including in the presence of unprotected cysteine residues) to provide native peptides.