Ketone is a class of chemical compounds contain the carbonyl group in which the
carbon atom is covalently bonded to an oxygen atom.
Carbonyl groups are:
- Aldehydes (X and Y = H; X = H, Y = alkyl or aryl)
- Ketones (X and Y = alkyl or aryl)
- Carboxylic acids (X = OH, Y = H, alkyl, or
aryl)
- Esters (X = O-alkyl or aryl; Y = H, alkyl, or aryl)
- Amides (X = NH,
N-alkyl, or N-aryl; Y = H, alkyl, or aryl)
- Acid halides
- Acid anhydrides
- Lactones
- Lactams
Ketone has the general formula
RCOR' where the groups R and R' may be the same or different, or incorporated
into a ring (R and R' are alkyl, aryl, or heterocyclic radicals). The simplest
example, R and R´ are methyl group, is acetone (also called 2-propanone,
CH3COCH3) which is one of the most important ketones used in industry (low
molecular weight ketones are general purpose solvents.) In the IUPAC system, the
suffix -one is used to describe ketone with the numbering of the carbon atom at
the end that gives the lower number. For example, CH3CH2COCH2CH2CH3 is named
3-hexanone because the whole chain contains six carbon atoms and the oxygen is
connected to the third carbon from the lower number. There are aromatic ketones of which acetophenone and bezophenone are examples. Ketones can be made by the
oxidation of secondary alcohols and the destructive distillation of certain
salts of organic acids. In addition to as polar solvents, ketones are important
intermediates in the syntheses of organic compounds such as alkoxides,
hydroxyalkynes, imines, alcohols (primary, secondary as well as tertiary),
acetals, thioacetals, phosphine oxides, geminal diols, hydrazones, organic
sulfite and cyanohydrins.
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