Tetra-n-butylammonium peroxydisulfate ( (n-$Bu_4N$)$_2S_2O_8$ ) has been successfully prepared and turned out to be a useful source of tetra-n-butyl ammonium sulfate radical in organic solvents. Various alkenes were reacted with tetra-n-butylammonium peroxydisulfate in anhydrous 1,3-dioxolane / acetonitrile mixture to give one carbon homologated products which were typed as masked formylating form. Mild and efficient conversion of oximes to ketones with $(TBA)_2S_2O_8$ was found also. Sulfate anion radical was found to oxidize the C=N bond of N,N-dimethyl hydrazone to ketone. Various oximes were treated with $(TBA)_2S_2O_8$ in 1,2-dichloroethane to give high yield of the corresponding ketones. This new reaction can be a good method for an efficient conversion of oximes to ketones under mild conditions. In due course of 1:1 addition of 1,3-dioxolane to alkenes, it has been also found that 1,1-diphenyl-2-vinyl cyclopropane reacted with tetra-n-butylammonium peroxydisulfate to give 2,2-diphenyl-4-oxetane.