Chemical conversion of cyclic .ALPHA.-amino acids to .ALPHA.-aminodicarboxylic acids by improved ruthenium tetroxide oxidation.

Abstract

The ruthenium tetroxide (RuO4) oxidation of N-acylated L-proline esters, prepared from L-proline, was carried out under two-phase conditions to afford good yields of the corresponding lactams with no appreciable racemization, and the products were hydrolyzed in aqueous hydrochloric acid to L-glutamic acid. Similar transformation starting with recemic 2-piperidinecarboxylic acid and 2-azetidinecarboxylic acid gave 2-aminoadipic acid and aspartic acid, respectively. A novel chemical conversion of cyclic α-amino acids into α-aminodicarboxylic acids has been accomplished. A new solvent system, ethyl acetate-water, was developed for this two-phase oxidation. It was found to be very useful in reducing the necessary reaction time.