| abstract |
A method for producing an α-aspartylphenylalanine derivative represented by formula (II) comprises reacting a β-aspartylphenylalanine derivative represented by formula (I)n wherein R₁ and R₂ represent hydrogen or an alkyl group having 1 to 4 carbon atoms, with a basic compound in a solvent in the presence of an inorganic compound or an organic compound of zinc, copper, nickel, magnesium, aluminum, iron, tin, silicon and/or titanium. |