The crystalline 2, 4-dinitrophenyl derivatives of the following L-amino acids have been prepared for the first time: valine, norvaline, isovaline, leucine, isoleucine, alloisoleucine, a- aminononylic acid, serine, 7-hydroxy-a-aminobutyric acid, E-hydroxy-a-aminocaproic acid, threonine, allothreonine, S-benzylcysteine, hydroxyproline, aspartic acid, glutamine, a, y- diaminobutyric acid, histidine, as well as those of DL-ethionine, DL-methionine, DL- ...
