Asymmetric synthesis of suitably protected γ-hydroxy-aza-β3-homothreonine building blocks

Abstract An efficient and easily applicable method for the enantioselective synthesis of γ-Hydroxy aza-β 3 -homothreonine (aza-β 3 -Hyht) has been established. The method involves stereoselective reductive amination of glyoxylic acid and the corresponding Fmoc protected chiral hydrazine. A stereoselectivity of 99% was achieved for each step using ( R )-2,3- O -isopropylideneglyceraldehyde as the chiral auxiliary. This new synthetic monomer is a useful building block for the solid-phase synthesis of new peptidomimetics.