Oxidizing agents producing quinones

Strong oxidizing agents convert the phenolic rings of calixarenes to quinones, as discussed above, but milder oxidizing agents produce compounds in which one... 

Dibenzofuran is highly stable to oxidizing agents. 2-Dibenzofuranol is oxidized to 2-(2-hydroxyphenyl)-l,4-benzoquinone by sodium periodate in aqueous acetic acid, whereas reaction of 1-dibenzofuranol or 4-dibenzo-furanols with Fremy s salt produces the dibenzofuran-l,4-quinones. The oxidation of dibenzofuran with microorganisms has been studied. A mutant strain of a Beijerinckia bacterium oxidizes dibenzofuran to a mixture of cis-2,3-dihydroxy-2,3-dihydrodibenzofuran and cis-l,2-dihy-droxy-l,2-dihydrodibenzofuran. The former compound was found to be too... 

A naive look at Table 6.1 would suggest that aldehydes, quinones and some ketones, like 1,3-dimethoxyacetone, would operate as very good oxidizing agents, allowing for example the preparation of aldehydes. In fact, these compounds possessing very high oxidation potentials are more reactive than simple ketones like cyclohexanone and tend to produce many side reactions, like aldol condensations. 

The Indulines are destroyed on oxidation, quinone being formed reducing agents produce easily oxidisable leuco-compounds. 

Oxidation of hydroquinone (1,4-benzenediol) produces a compound known as p-benzo-quinone. The oxidation can be brought about by mild oxidizing agents, and, overall, the oxidation amounts to the removal of a pair of electrons (2 e ) and two protons from hydroquinone. (Another way of visuahzing the oxidation is as the loss of a hydrogen molecule, H H, making it a dehydrogenation.)... 

Quinone is produced in small yield by direct oxidation of benzene itself with silver peroxide, but better by the action of oxidising agents on a large number of its p-disubstitution products. Thus, in addition to quinol, p-aminophenol (experiment, p. 176), p-anisidine, p-toluidine, and sulphanilic acid as well as p-phenylenediamine and many of its derivatives yield quinone in this way. 

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