Hydrogen Peroxide Oxidation. I. A New Selenium Dioxide-Catalyzed Synthesis of Carboxylic Acids from Aliphatic Ketones Accompanied by Rearrangement of Alkyl Groups

Abstract 1) Selenium dioxide catalyzed oxidation of aliphatic ketones with hydrogen peroxide gave carboxylic acids which were produced by the rearrangement of the alkyl group as shown by equation 5. 2) Acetone, methyl ethyl ketone, methyl n-propyl ketone and diethyl ketone were selected as starting materials. The main rearrangement observed is due to the migration of the alkyl group having a smaller number of carbon atoms to the α-carbon atom of the larger alkyl group, and the migration of the alkyl group with a larger number of carbon atoms to the smaller one also occurs in some degree. 3) The yield of the generated acids were about 30∼40% of the theoretical amounts based on the ketones used. Small amounts of cleavage products were obtained as the by-products in all cases. Both of the cleavaged groups from a ketone were oxidized to acids in these reaction systems. 4) The most probable catalytic form seems to be peroxyselenious acid which may be produced by the oxidation of selenium dioxide with hydrogen peroxide (equation 6). Inferential reaction mechanism was discussed.