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2-Pyrone

2-Pyrone^[1]

IUPAC name	Pyran-2-one
Other names	α-Pyrone 2-Pyranone 2H-Pyran-2-one
Identifiers
CAS number	504-31-4
PubChem	68154
SMILES	C1=CC(=O)OC=C1
Properties
Molecular formula	C₅H₄O₂
Molar mass	96.08
Density	1.197 g/mL
Boiling point	102-103 °C at 20 mmHg
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and 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.

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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]

2-Pyrone also forms the the core structure of a variety of natural organic compounds. For example, the coumarins are an important class of compounds which are benzo-fused derivatives of 2-pyrone.

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.

Category: Lactones