A Facile Synthesis of Differently Protected Cystathionines in Aqueous Solutions

A simple method for the synthesis of differently protected cystathionines is described. Reaction of γ- bromohomoalanine with cysteine derivatives in an ethyl acetate/water two-phase system, which contains TBAHS and NaHCO3, led to the desired protected cystathionines in very high to excellent yields. Apart from the high yields, the mild conditions and the ease of conducting the reactions are also attractive features for this procedure.