Studies on optically active amino acids. IX. Studies on alpha-alkyl-alpha-amino acids. IV. Chemical correlation of absolute configuration of alpha-methylaspartic acid to isovaline

Crystal structure of (S)-2-amino-2-methyl-succinic acid

The title compound, C5H9NO4, crystallized as a zwitterion. There is an intra-molecular N-H⋯O hydrogen bond involving the trans-succinic acid and the ammonium group, forming an S(6) ring motif. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming C(7) chains along the c-axis direction. The chains are linked by N-H⋯O and C-H⋯O hydrogen bonds, forming sheets parallel to the bc plane. Further N-H⋯O hydrogen bonds link the sheets to form a three-dimensional framework.