Pd(OH)2/C-Mediated Selective Oxidation of Silyl Enol Ethers by tert-Butylhydroperoxide, a Useful Method for the Conversion of Ketones to α,β-Enones or β-Silyloxy-α,β-enones

[reaction: see text] Pd(OH)2-catalyzed oxidation of silyl enol ethers by t-BuOOH gives either beta-silyloxy-alpha,beta-enones or alpha,beta-enones in good yields depending on the base used.