Cyclononatetraene

Cyclononatetraene
Names
	IUPAC name Cyclonona-1,3,5,7-tetraene
Identifiers
CAS Number	7129-70-6;
3D model (JSmol)	Interactive image;
ChemSpider	11341386;
PubChem CID	12543719;
CompTox Dashboard (EPA)	DTXSID40499530 ;
	InChI InChI=1S/C9H10/c1-2-4-6-8-9-7-5-3-1/h1-8H,9H2/b3-1-,4-2-,7-5-,8-6- Key: GORPVKZVZYAFSO-KZPCVFJPSA-N;
	SMILES C\1/C=C\C=C/C=C\C=C1;
Properties
Chemical formula	C9H10
Molar mass	118.179 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Cyclononatetraene is an organic compound with the formula C₉H₁₀. It was first prepared in 1969 by protonation of the corresponding aromatic anion (described below).^[1] It is unstable and isomerizes with a half-life of 50 minutes at room temperature to 3a,7a-dihydro-1H-indene via a thermal 6π disrotatory electrocyclic ring closing.^[2] Upon exposure to ultraviolet light, it undergoes a photochemical 8π electrocyclic ring closing to give bicyclo[6.1.0]nona-2,4,6-triene.^[3]

^ Radlick, Phillip; Alford, Gary (November 1969). "Preparation and isolation of cis, cis, cis, cis-1,3,5,7-cyclononatetraene". Journal of the American Chemical Society. 91 (23): 6529–6530. doi:10.1021/ja01051a083. ISSN 0002-7863.^{[permanent dead link]}
^ Radlick, Phillip; Gary Alford (1969), "Preparation and isolation of cis, cis, cis, cis-1,3,5,7-cyclononatetraene", Journal of the American Chemical Society, 91 (23): 6529–6530, doi:10.1021/ja01051a083
^ de Meijere, Armin, ed. (2014). Houben-Weyl Methods of Organic Chemistry Vol. E 17b, 4th Edition Supplement: Carbocyclic Three-Membered Ring Compounds, Cyclopropanes: Synthesis. Goettingen: Georg Thieme Verlag. p. 1226. ISBN 978-3131819543.

[1] Radlick, Phillip; Alford, Gary (November 1969). "Preparation and isolation of cis, cis, cis, cis-1,3,5,7-cyclononatetraene". Journal of the American Chemical Society. 91 (23): 6529–6530. doi:10.1021/ja01051a083. ISSN 0002-7863.^{[permanent dead link]}

[2] Radlick, Phillip; Gary Alford (1969), "Preparation and isolation of cis, cis, cis, cis-1,3,5,7-cyclononatetraene", Journal of the American Chemical Society, 91 (23): 6529–6530, doi:10.1021/ja01051a083

[3] Meijere, Armin, ed. (2014). Houben-Weyl Methods of Organic Chemistry Vol. E 17b, 4th Edition Supplement: Carbocyclic Three-Membered Ring Compounds, Cyclopropanes: Synthesis. Goettingen: Georg Thieme Verlag. p. 1226. ISBN 978-3131819543.

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