A<unk>  (pronounced as key tone) is either the functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms or a chemical compound that contains this functional group. A<unk>  can be generally represented by the formula:
A carbonyl carbon bonded to two carbon atoms distinguishes<unk> s from carboxylic acids, aldehydes, esters, amides, and other oxygen-containing compounds. The double-bond of the carbonyl group distinguishes<unk> s from alcohols and ethers.  
The simplest<unk>  is acetone (systematically named 2-propanone).
The carbon atom adjacent to a carbonyl group is called the α-carbon. Hydrogens attached to this carbon are called α-hydrogens. In the presence of an acid catalyst the<unk>  is subjected to so-called<unk> nol tautomerism. The reaction with a strong base gives the corresponding enolate. A diketone is a compound containing two<unk>  groups.
Ketone
Ketamine
Carbamate
Propofol
Methylpentynol
Halothane
Isoflurane
Alkane