Jones-Oxidation

Jones oxidation is a chemical reaction of the organic chemistry, which is the oxidation of alcohols and aldehydes. Primary alcohols are here first to aldehydes, then oxidized to carboxylic acids, secondary alcohols to ketones. As the oxidizing agent is chromium (VI ) oxide, which is reduced to chromium (IV), and subsequently chrome (III) and chromium (VI) disproportionates. The reaction is usually carried out in concentrated sulfuric acid in the presence of acetone ( Jones reagent ). In contrast to the Swern oxidation and Dess-Martin oxidation of alcohol used in a strongly acidic medium must be stable. The Jones oxidation is rarely used, since chromium (VI ) oxide, are highly toxic, carcinogenic and mutagenic, and the resulting chromium waste must also be disposed consuming.

Mechanism

The mechanism of the Jones oxidation is not completely understood. The mechanism specified here is only one of several possible options. Here, the alcohol initially engages in nucleophilic at the chromium core. The alcohol is deprotonated and it comes to the α -H elimination with elimination of chromium species and the formation of a carbonyl.

Use

Due to their hazardous nature, the Jones oxidation should, if possible, be replaced by equivalent reactions such as the Swern oxidation. It can only be used for the synthesis of ketones and acids. Stopping the reaction on the level of aldehydes is not possible. Existing in the substrate double bonds are usually not attacked.

Swell

• K. Bowden, I. M. Heilbron, E. R. H. Jones, B. C. L. Weedon: Researches on Acetylenic compounds. In: Journal of the Chemical Society. 39, 1946.
• Reinhard Brückner: reaction mechanisms. 3rd edition. Elsevier, Munich 2004, ISBN 3-8274-1579-9, pp. 742 f

• Name reaction