Hydroxy ketone

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Alpha- and beta-hydroxy ketones Hydroxyketone.svg
Alpha- and beta-hydroxy ketones

In organic chemistry, a hydroxy ketone (often referred to simply as a ketol) is a functional group consisting of a ketone (>C=O) flanked by a hydroxyl group (−OH). Chemicals in this group can be classified by the position of the hydroxyl relative to the ketone. The two main classes have the hydroxyl on the alpha or beta carbon, that is, on the immediately adjacent carbon or the next-further carbon, respectively. Thus, the general structure of the two main classes are R−C(=O)−CR'(OH)−R" (alpha) and R−C(=O)−CH2−C(OH)−R' (beta).

Alpha-hydroxy ketones are also called acyloins. [1] They are commonly formed by condensation or reductive coupling of two carbonyl (C=O) compounds or oxidation of ketones. The simplest such compound is hydroxyacetone. If the alcohol is primary, alpha-hydroxy ketones give a positive Fehling's test.

Beta-hydroxy ketones are a type of aldol. They are commonly formed by an aldol reaction between two carbonyl compounds. A simple example is diacetone alcohol.

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<span class="mw-page-title-main">Carboxylic acid</span> Organic compound containing a –C(=O)OH group

In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group. The general formula of a carboxylic acid is often written as R−COOH or R−CO2H, sometimes as R−C(O)OH with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion.

<span class="mw-page-title-main">Ester</span> Compound derived from an acid

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<span class="mw-page-title-main">Ketone</span> Organic compounds of the form >C=O

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<span class="mw-page-title-main">Aldol reaction</span> Chemical reaction

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<span class="mw-page-title-main">Hemiaminal</span> Organic compound or group with a hydroxyl and amine attached to the same carbon

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<span class="mw-page-title-main">Acyloin</span> Organic compounds of the form –C(=O)C(OH)–

In organic chemistry, acyloins or α-hydroxy ketones are a class of organic compounds of the general form R−C(=O)−CR'(OH)−R", composed of a hydroxy group adjacent to a ketone group. The name acyloin is derived from the fact that they are formally derived from reductive coupling of carboxylic acyl groups. They are one of the two main classes of hydroxy ketones, distinguished by the position of the hydroxy group relative to the ketone; in this form, the hydroxy is on the alpha carbon, explaining the secondary name of α-hydroxy ketone.

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<span class="mw-page-title-main">Vinylogy</span> Transmission of electronic effects through a system of conjugated chemical bonds

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<span class="mw-page-title-main">Mukaiyama Taxol total synthesis</span>

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References

  1. IUPAC , Compendium of Chemical Terminology , 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006) " acyloins ". doi : 10.1351/goldbook.A00126

See also