Synthesis of ω-tert-butyl esters of aspartic acid and glutamic acid via B,B-difluoroboroxazolidones

Abstract

B,B-Difluoroboroxazolidones (DFBONs) were synthesized for the first time from salts of amino acid and BF3·Et2O, and their properties were examined. DFBONs were used in selective preparation of Glu(OBu(t)) and Asp(OBu(t)) in good yields under catalysis with BF3·Et2O and H3PO4. Amberlite XAD-2 resin was successfully employed to purify the above amino acid derivatives.