Editing Ketone (section)

===Classes of ketones===
Ketones are classified on the basis of their substituents. One broad classification subdivides ketones into symmetrical and unsymmetrical derivatives, depending on the equivalency of the two organic substituents attached to the carbonyl center. Acetone and [[benzophenone]] ({{chem2|(C6H5)2CO}}) are symmetrical ketones. [[Acetophenone]] {{chem2|(C6H5C(O)CH3)}} is an unsymmetrical ketone.

====Diketones====
{{main|dicarbonyl}}
Many kinds of diketones are known, some with unusual properties. The simplest is [[diacetyl]] {{chem2|(CH3C(O)C(O)CH3)}}, once used as butter-flavoring in [[popcorn]]. [[Acetylacetone]] (pentane-2,4-dione) is virtually a misnomer (inappropriate name) because this species exists mainly as the monoenol {{chem2|CH3C(O)CH\dC(OH)CH3}}. Its enolate is a common ligand in [[coordination chemistry]].

====Unsaturated ketones====
Ketones containing [[alkene]] and [[alkyne]] units are often called unsaturated ketones. A widely used member of this class of compounds is [[methyl vinyl ketone]], {{chem2|CH3C(O)CH\dCH2}}, a  [[α,β-Unsaturated carbonyl compound|α,β-unsaturated carbonyl compound]].

====Cyclic ketones====
Many ketones are cyclic. The simplest class have the formula {{chem2|(CH2)_{''n''}CO}}, where ''n'' varies from 2 for [[cyclopropanone]] ({{chem2|(CH2)2CO}}) to the tens. Larger derivatives exist. [[Cyclohexanone]] ({{chem2|(CH2)5CO}}), a symmetrical cyclic ketone, is an important intermediate in the production of [[nylon]]. [[Isophorone]], derived from acetone, is an unsaturated, asymmetrical ketone that is the precursor to other [[polymer]]s. [[Muscone]], 3-methylpentadecanone, is an animal [[pheromone]]. Another cyclic ketone is [[cyclobutanone]], having the formula {{chem2|(CH2)3CO}}.