ketone, any of a class of organic compounds that contain the carbonyl group, C--O, and in which the carbonyl group is bonded only to carbon atoms. The general formula for a ketone is RCOR', where R and R' are alkyl or aryl groups. The simplest ketone, where R and R' are methyl groups, is acetone; this is one of the most important ketones used in industry. Low-molecular-weight ketones are used chiefly as solvents. Ketones may be prepared by several methods, including the oxidation of secondary alcohols and the destructive distillation of certain salts of organic acids. Ketones are related to the aldehydes but are less active chemically.

dimethyl ketone: see acetone.

Any of a class of organic compounds containing a carbonyl group (singlehorzbondCdoublehorzbondO; see functional group) bonded to two carbon atoms. Ketones can participate in many chemical reactions, though to a lesser extent than the related aldehydes. Many more complex organic compounds have ketones as building blocks. Their chief industrial use is as solvents and in the manufacture of explosives, lacquers, paints, and textiles. Acetone is the most important ketone; several sugars and some natural and synthetic steroids are ketones. In ketosis, ketones produced by lipid metabolism accumulate in the blood and urine in abnormal amounts, usually because of starvation or a metabolic disease such as diabetes mellitus.

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or dimethyl ketone

Simplest and most important ketone (CH₃COCH₃). It is a colourless, flammable liquid, boiling at 133 °F (56.2 °C). Many fats, resins, and organic materials dissolve easily in it, so it is used to make artificial fibres, explosives, resins, paints, inks, cosmetics (including nail-polish remover), coatings, and adhesives. Acetone is used as a chemical intermediate in pharmaceuticals and many other compounds.

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