2-Pyrone

2-Pyrone^[1]
Names
	IUPAC name Pyran-2-one
	Other names α-Pyrone; 2-Pyranone; 2H-Pyran-2-one
Identifiers
CAS Number	504-31-4;
3D model (JSmol)	Interactive image;
ChemSpider	61462;
ECHA InfoCard	100.007.264
PubChem CID	68154;
CompTox Dashboard (EPA)	DTXSID50198441 ;
	InChI InChI=1/C5H4O2/c6-5-3-1-2-4-7-5/h1-4H Key: ZPSJGADGUYYRKE-UHFFFAOYAI;
	SMILES O=C\1O\C=C/C=C/1;
Properties
Chemical formula	C5H4O2
Molar mass	96.08
Density	1.197 g/mL
Boiling point	102-103 °C at 20 mmHg
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

2-Pyrone (α-pyrone or pyran-2-one) is an unsaturated cyclic chemical compound with the molecular formula C₅H₄O₂. It is isomeric with 4-pyrone.

2-Pyrone is used in organic synthesis as a building block for more complex chemical structures because it may participate in a variety of cycloaddition reactions to form bicyclic lactones. For example, it readily undergoes Diels-Alder reactions with alkynes producing, upon loss of carbon dioxide, substituted benzenes.^[2]. The Gogte Synthesis (1938) is a method for the alkylation of certain pyrones with acid chlorides ^{[citation needed]}.

4-Pyrone

The most famous natural products are Bufanolides and Kavalactones or Kavapyrones.

References

^ 2H-Pyran-2-one at Sigma-Aldrich
^ Woodard BT, Posner G H. "Recent Advances in Diels-Alder Cycloadditions Using 2-Pyrones." Advances in Cycloaddition. 1999, 5, 47-83.

[1] 2H-Pyran-2-one at Sigma-Aldrich

[2] Woodard BT, Posner G H. "Recent Advances in Diels-Alder Cycloadditions Using 2-Pyrones." Advances in Cycloaddition. 1999, 5, 47-83.

[1]

[2]