SELECTIVE CATALYTIC-OXIDATION OF GLYCERIC ACID TO TARTRONIC AND HYDROXYPYRUVIC ACIDS

The catalytic oxidation, with air, of aqueous solutions of glycerol-de rived oxygenates on carbonsupported platinum metals may be controlled to improve yields of valuable fine chemicals. The primary and secondar y alcohol functions of glyceric acid, calcium salt, were selectively o xidised by varying the pH and employing a promoter. Under basic condit ions, platinum catalyst yielded the tartronate salt (61% yield at 94% conversion, pH 10-11) and slightly higher yields were obtained on bism uth-promoted platinum (83% yield at 90% conversion, pH = 10-11). Hydro xypyruvic acid was obtained on bismuth-promoted platinum under acidic conditions (64% yield at 75% conversion, pH 3-4).