OXIDATIVE CLEAVAGE OF METHYL ETHERS USING THE HOF-CENTER-DOT-CH3CN COMPLEX

HOF . CH3CN complex, made easily by bubbling fluorine diluted with nit rogen through aqueous acetonitrile, proved to be a suitable oxidizer f or various methyl ethers. Secondary ethers are oxidized to ketones and even to lactones via Baeyer-Villiger type of oxidation. The reaction is ionic, and the reagent's electrophilic oxygen attacks the relativel y electron rich C-H bend alpha to the ether moiety. It was found that the more sterically hindered is the C-H bond in question, the slower t he reaction. In cases where this bond is an electron poor one as in be nzoin methyl ether (9), no reaction takes place. When labeled (HOF)-O- 18 . CH3CN is used on a O-16 methyl ether, the resulting ketone posses ses only the heavier oxygen isotope. Primary methyl ethers are somewha t slower to react, but they too were oxidized in very good yields to a cids via the corresponding aldehydes.