{{Short description|Class of chemical compounds}} [[Image:2-Pyranone.png|thumb|right|75px|2-Pyrone]] [[Image:4-Pyranone.png|thumb|right|75px|4-Pyrone]] '''Pyrones''' or '''pyranones''' are a class of heterocyclic chemical compounds. They contain an unsaturated six-membered ring, which has one oxygen atom and a carbonyl functional group.<ref>{{cite book |title=Introduction to Organic Chemistry |first1=Andrew Jr.|last1=Streitwieser |author-link1=Andrew Streitwieser |first2=Clayton H. |last2=Heathcock |author-link2=Clayton Heathcock |edition=Third |pages=[https://archive.org/details/introductiontoor0003stre/page/1038 1038–1040] |isbn=978-0-02-418140-4 |year=1985 |url=https://archive.org/details/introductiontoor0003stre/page/1038 }}</ref> There are two isomers, denoted as 2-pyrone and 4-pyrone. The 2-pyrone (or α-pyrone) structure is a lactone and is found in nature as part of the coumarin ring system. The 4-pyrone (or γ-pyrone) structure is an ether–ketone found in some natural chemical compounds such as chromone, maltol and kojic acid.
3-pyrones are zwitterionic, unstable carbonyl ylides. They intermediate some cycloadditions.<ref>{{cite news|url=https://www.organic-chemistry.org/Highlights/2020/06July.shtm|website=Organic Chemistry Highlights|title=The Li synthesis of vinigrol|date=July 6, 2020|first=Douglass F.|last=Taber}}</ref>
== See also == * Furanone, which has one fewer carbon atom in the ring. * Pyridones, which contain a nitrogen in place of the oxygen that is part of the ring
==References== {{Reflist}} {{heterocyclic-stub}} Category:Pyrones