OXYGENATION OF SILYL ENOL ETHERS AND SILYL KETENE ACETALS WITH MOLECULAR-OXYGEN AND ALDEHYDE CATALYZED BY NICKEL(II) COMPLEX - A CONVENIENT METHOD FOR THE PREPARATION OF ALPHA-HYDROXY CARBONYL-COMPOUNDS
In the presence of a catalytic amount of nickel(II) complex, silyl enol ethers and silyl ketene acetals are smoothly oxygenated by the combined use of molecular oxygen and aldehyde to afford alpha-siloxy carbonyl compounds via possible intermediates, siloxy expoxides. And on treatment of the alpha-siloxy carbonyl compounds with potassium fluoride alpha-hydroxy carbonly compounds are obtained in good to high yields.