Manganese-Catalyzed Oxidative Transformation of Silyl Ethers to Ketones: Enantioselective Synthesis of Optically Active β- and γ-Siloxyketones

(Salen)manganese(III)-catalyzed oxidation of silyl ethers with iodosylbenzene gave the corresponding carbonyl compounds. The enantioselective oxidation of symmetrical 1,3- and 1,4-disilyl ethers gave the corresponding optically active β- and γ-siloxyketones, respectively (up to 93% ee).