Konstitutionsermittlung der Isomeren der γ-Amino-β-hydroxy-buttersäure durch erschöpfende Methylierung

Abstract

The 4 active forms of alpha-amino-beta-hydroxy-butyric acid (1) consist of the 1- and d-isomers of the open chain form, and the 1- and d-forms of the betaine form. On treatment of the open chain form with methyl iodide and potassium hydroxide at room temperature the amino- group is dimethylated and the carboxyl is esterified; under the same conditions the betaine form yields gamma-trimethyl-[beta]-hydroxy-butyro-betaine. The latter does not give a biuret reaction, whereas the ester does. The 2 derivatives have also been differentiated by their Debye-Scherrer X-ray diagrams.