Methyl octyl ketone, oxidation

A combination of bromide ions and methyl octyl sulphide is able to oxidise secondary alcohols at the potential necessary to fonn bromine. Conversion of the alcohol to the ketone follows the Scheme 8.2 and uses an undivided cell with benzo-nitrile as the solvent containing 2,6-lutidine as base and tetraethylamnionium bromide. The reaction occurs using a platinum anode at 1.1 V vs-, see [28], Thio-anisole alone, in absence of bromide, will function as a catalyst for the oxidation of secondary alcohols but in these cases a more positive anode potential of 1.5 V vs. see is needed to oxidise the thioether [29]. 

The most characteristic property of the bismuthine oxides is their oxidizing ability to convert activated alcohols, triphenylphosphine and hydrazobenzene to the corresponding ketones, oxide and azo compound, respectively. However, thioanisole and methyl octyl sulfide remain intact even after prolonged stirring with bismuthine oxide at ambient temperature [94TL8197] (Section 5.2.4). 

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