1.2- Cyclohexanediol oxidative cleavage

Although carbinols were found not to be oxidized by lead tetraacetate in acetic acid, they were attacked in less polar solvents, and glycol-cleavage was also more rapid in these solvents23 for example, the rate of oxidation of trans-l, 2-cyclohexanediol in tetrachloroethane was 5,000 times that in acetic acid. The kinetics was no longer true second-order in the media of low polarity, but approached this state as the concentration of acetic acid... 

The oxidation of vic-diols is often accompanied by cleavage of the C-C bond to yield ketones and/or aldehydes. Especially the clean conversion of (cyclohexene to) 1,2-cyclohexanediol to adipic acid (Fig. 4.76) has received tremendous interest [229]. 

The mechanism of 1,2-cleavage of glycols with sodium bismuthate is generally considered to be similar to that with lead tetraacetate and periodic acid [40CB563], although there is still some controversy [50JCS(C)1907]. A cyclic bismuthate diester is postulated as a plausible intermediate, though the rates of oxidation observed are not so different between cis- and trans-, 2-cyclohexanediols. 

Silver oxide can also oxidize primary alcohols directly to the acid, as in the oxidation of 1-dodecanol to dodecanoic acid. Oxidation of 1,2-diols is accompanied by cleavage to the diacid (sec. 3.7.C), as in the conversion of 1,2-cyclohexanediol to adipic acid in 89% yield. ... 

The PW4O2J anion turned out to be a valuable catalyst for a number of oxidations of organic substrates with hydrogen peroxide, including the epoxidation of olefins and their cleavage, e.g. to get adipic acid from cyclohexene or from the intermediate 1,2-cyclohexanediol. " ... 

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