Cupric permanganate oxidant

Cupric permanganate, Cu(Mn04)2 8H20, is commercially available and oxidizes primary alcohols and aldehydes to acids, secondary alcohols to ketones, and sulfides to sulfones in very high yields [894]. 

Biphenyl coupling occurs to some extent on cupric oxide oxidation of lignin model compounds [55,56]. This indicates that the value derived from permanganate oxidation studies is slightly too high. On the basis C NMR examinations, Drumond et al. [57] arrived at a higher value for the frequency of biphenyl units (24-26%). The accuracy of this estimate can be questioned, since no separate signals from biphenyl units can be discerned in the spectra. 

The immediate outcome of the Hantzsch synthesis is the dihydropyridine which requires a subsequent oxidation step to generate the pyridine core. Classically, this has been accomplished with nitric acid. Alternative reagents include oxygen, sodium nitrite, ferric nitrate/cupric nitrate, bromine/sodium acetate, chromium trioxide, sulfur, potassium permanganate, chloranil, DDQ, Pd/C and DBU. More recently, ceric ammonium nitrate (CAN) has been found to be an efficient reagent to carry out this transformation. When 100 was treated with 2 equivalents of CAN in aqueous acetone, the reaction to 101 was complete in 10 minutes at room temperature and in excellent yield. 

A SELECTIVE, HETEROGENEOUS OXIDATION USING A MIXTURE OF POTASSIUM PERMANGANATE AND CUPRIC SULFATE (3aS,7aR)-HEXAHYDRO-(3S,6R)-DIMETHYL-2(3H)-BENZOFURANONE (2(3H)-Benzofuranone, hexahydro-3,6-dimethyl-,... 

Sulphates of the alkali and alkaline earth metals, when heated with sulphur, are converted into sulphide, polysulphide and thiosulphate, with simultaneous formation of sulphur dioxide many other sulphates, e.g. those of copper, mercury, silver and lead, yield only sulphide.7 Other salts of the metals behave in a similar- manner, undergoing transformation into sulphides, the change being effected more readily with the salts of the heavy metals, many of which indeed react slowly with sulphur even at 100° C. in the presence of water.8 At 150° to 200° C. mercuric, stannic and ferric salts in aqueous solution are quantitatively reduced by sulphur mercurous, cupric, bismuth and lead salts arc slowly but quantitatively precipitated as sulphides. Nitrates, permanganates and iodates cause oxidation of the sulphur to sulphuric acid. 

Hydrogen trisulphide is much more easily combustible than the crude parent hydrogen polysulphide. Exposure to light tends to accelerate its decomposition. It slowly reduces concentrated sulphuric acid to sulphur dioxide, whilst on contact with dry silver oxide, cupric oxide, lead dioxide or mercuric oxide, it bursts into explosive combustion,2 a residue of the metallic sulphide being obtained. Many other metallic oxides and most salts bring about a less vigorous decomposition metals in the massive condition only react with it slowly. With potassium permanganate or dichromate the reaction is violent. 

Tropolone itself can be prepared in a number of ways, the most convenient of which involves oxidation of 1,3,5-cycloheptatriene with alkaline potassium permanganate. The yield is low but the product is isolated readily as the cupric salt ... 

The oxidation of silanes also can be accomplished by solutions of potassium permanganate, mercuric salts, ferric compounds, and cupric salts. Plain water also will oxidize the silicon-hydrogen bond in the presence of hydroxyl ions as catalysts 6... 

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