Stereoselective sodium borohydride reduction, catalyzed by manganese(II) chloride, of γ-oxo-α-amino acids. A practical approach to syn-γ-hydroxy-α-amino acids

A highly stereoselective reduction of γ-oxo-α-amino acids by sodium borohydride in the presence of a catalytic amount of manganese(II) chloride gives syn-γ-hydroxy-α-amino acids. Enantiomerically pure syn-(2S,4R,1′S)-4-aryl-4-hydroxy-2-(1′-phenylethylamino)butanoic acids form stable gels in methanol.