抄録
The enantioselective addition of chiral benzylic amines to dimethyl maleate and fumarate gives optically active aspartic acid in satisfactory yields. The re-face favorably meets the stereochemical requirements of the chiral R-amines than does the si-face. The stereoselectivity in the present reaction is little dependent on solvent polarity but is significantly enhanced by low temperature. The direct determination by gas-liquid chromatography of the diastereomeric addition products provides more precise values of optical yield and is preferred to the polarimetry of the end product after many steps of transformation with probable fractionations.
