Diketene

Diketene

Names
Preferred IUPAC name 4-Methylideneoxetan-2-one
Other names γ-Methylenepropiolactone
Identifiers
CAS Number	674-82-8 Y
3D model (JSmol)	Interactive image
ChemSpider	12140 Y
ECHA InfoCard	100.010.562
EC Number	211-617-1
PubChem CID	12661
RTECS number	RQ8225000
UNII	0DZ97C3Z7D
UN number	2521
CompTox Dashboard (EPA)	DTXSID9027289
InChI InChI=1S/C4H4O2/c1-3-2-4(5)6-3/h1-2H2 Y Key: WASQWSOJHCZDFK-UHFFFAOYSA-N Y InChI=1/C4H4O2/c1-3-2-4(5)6-3/h1-2H2 Key: WASQWSOJHCZDFK-UHFFFAOYAM
SMILES O=C1OC(=C)C1
Properties
Chemical formula	C4H4O2
Molar mass	84.074 g·mol−1
Density	1.09 g cm−3
Melting point	−7 °C (19 °F; 266 K)
Boiling point	127 °C (261 °F; 400 K)
Viscosity	0.88 mPa.s
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H226, H301, H302, H315, H318, H330, H331, H332, H335
Precautionary statements	P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P280, P284, P301+P310, P301+P312, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P311, P312, P320, P321, P330, P332+P313, P362, P370+P378, P403+P233, P403+P235, P405, P501
Flash point	33 °C (91 °F; 306 K)
Autoignition temperature	275
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Diketene is an organic compound with the molecular formula C₄H₄O₂, and which is sometimes written as (CH₂CO)₂. It is formed by dimerization of ketene, H₂C=C=O. Diketene is a member of the oxetane family. It is used as a reagent in organic chemistry.^[1] It is a colorless liquid.