Anodic oxidation of 1,1-diphenyl-2-methyl-propene (1) in an acetonitrile-methanol mixture under argon gave 3,3-diphenyl-2-butanone (2) in high yield together with small amounts of 1,2-diphenyl-2-methyl-1-propanone (3) and benzophenone (4). Similar anodic oxidation of 1 in the presence of oxygen was also carried out, and the mechanisms for the novel ketone forming reactions are discussed.