Editing Cyclohexene

{{chembox
| Watchedfields = changed
| verifiedrevid = 414090407
| ImageFileL1 = Olefine am Beispiel von Cycloalken-v2.svg
| ImageFileR1 = Cyclohexene for highscool.svg
| ImageFileL2 = Cyclohexene-conformation-2D-skeletal.png
| ImageFileR2 = Cyclohexene-from-xtal-3D-bs-17.png
| PIN = Cyclohexene <!-- Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) -->
| OtherNames = Tetrahydrobenzene, 1,2,3,4-Tetrahydrobenzene, Benzenetetrahydride, Cyclohex-1-ene, Hexanaphthylene, UN 2256
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 7788
| InChIKey = HGCIXCUEYOPUTN-UHFFFAOYAQ
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 16396
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C6H10/c1-2-4-6-5-3-1/h1-2H,3-6H2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = HGCIXCUEYOPUTN-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 110-83-8
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 12L0P8F7GN
| EINECS = 203-807-8
| PubChem = 8079
| SMILES = C1CCC=CC1
| InChI = 1/C6H10/c1-2-4-6-5-3-1/h1-2H,3-6H2
| RTECS = GW2500000
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 36404
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG =
| Gmelin = 1659
| Beilstein = 906737
  }}
|Section2={{Chembox Properties
| Formula = C<sub>6</sub>H<sub>10</sub>
| MolarMass = 82.143 g/mol
| Appearance = colorless liquid
| Odor = sweet
| Density = 0.8110 g/cm<sup>3</sup>
| MeltingPtC = -103.5
| BoilingPtC = 82.98
| Solubility = slightly soluble in water
| SolubleOther = miscible with organic solvents
| VaporPressure = 8.93 kPa (20 °C)
11.9 kPa (25 °C)
| HenryConstant = 0.022 mol·kg<sup>−1</sup>·bar<sup>−1</sup>
| RefractIndex = 1.4465
| MagSus = −57.5·10<sup>−6</sup> cm<sup>3</sup>/mol
  }}
|Section3={{Chembox Hazards
| ExternalSDS = [http://www.sciencelab.com/msds.php?msdsId=9923626 External MSDS]
| MainHazards =
| NFPA-H = 1
| NFPA-F = 3
| NFPA-R = 0
| NFPA-S =
| GHSPictograms = {{GHS02}}{{GHS06}}{{GHS07}}{{GHS08}}{{GHS09}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|225|302|305|311|411}}
| PPhrases = {{P-phrases|210|233|240|241|242|243|264|270|273|280|301+310|301+312|302+352|303+361+353|312|322|330|331|361|363|370+378|391|403+235|405|501}}
| FlashPtC = -12
| AutoignitionPtC = 244
| ExploLimits = 0.8–5%
| LD50 = 1407 mg/kg (oral, rat)
| PEL = TWA 300 ppm (1015 mg/m<sup>3</sup>)<ref name=PGCH>{{PGCH|0167}}</ref>
| IDLH = 2000 ppm<ref name=PGCH/>
| REL = TWA 300 ppm (1015 mg/m<sup>3</sup>)<ref name=PGCH/>
| LCLo = 13,196 ppm (mouse, 2 hr)<ref>{{IDLH|110838|Cyclohexene}}</ref>
  }}
}}

'''Cyclohexene''' is a [[hydrocarbon]] with the formula {{chem2|(CH2)4C2H2}}. It is a [[cycloalkene]]. At room temperature, cyclohexene is a colorless [[liquid]] with a sharp odor. Among its uses, it is an [[chemical intermediate|intermediate]] in the commercial synthesis of [[nylon]].<ref>{{cite journal|doi=10.1038/s41467-024-46556-6 |title=Complete separation of benzene-cyclohexene-cyclohexane mixtures via temperature-dependent molecular sieving by a flexible chain-like coordination polymer |date=2024 |last1=Xie |first1=Feng |last2=Chen |first2=Lihang |last3=Cedeño Morales |first3=Eder Moisés |last4=Ullah |first4=Saif |last5=Fu |first5=Yiwen |last6=Thonhauser |first6=Timo |last7=Tan |first7=Kui |last8=Bao |first8=Zongbi |last9=Li |first9=Jing |journal=Nature Communications |volume=15 |issue=1 |page=2240 |pmid=38472202 |pmc=10933443 |bibcode=2024NatCo..15.2240X }}</ref>

==Production and uses==
Cyclohexene is produced by the partial [[hydrogenation]] of [[benzene]], a process developed by the [[Asahi Chemical]] company.<ref>{{cite patent|title=Cyclohexanol, method for producing cyclohexanol, and method for producing adipic acid|pubdate=26 Sep 2017|inventor-last=Narisawa|inventor2-last=Tanaka|inventor-first=Naoki|inventor2-first=Katsutoshi|country=US|number=9771313}}</ref>  The main product of the process is cyclohexane because cyclohexene is more easily hydrogenated than benzene.

In the laboratory, it can be prepared by [[dehydration reaction|dehydration]] of [[cyclohexanol]].<ref>{{cite journal |doi=10.15227/orgsyn.005.0033|title=Cyclohexene|journal=Organic Syntheses|year=1925|volume=5|page=33|author=G. H. Coleman, H. F. Johnstone}}</ref>
:{{chem2|C6H11OH  ->  C6H10  +  H2O}}

==Reactions and uses==
Benzene is converted to [[cyclohexylbenzene]] by acid-catalyzed alkylation with cyclohexene.<ref>{{cite journal |doi=10.15227/orgsyn.019.0036|title=Cyclohexylbenzene|journal=Organic Syntheses|year=1939|volume=19|page=36|author=B. B. Corson, V. N. Ipatieff}}</ref> Cyclohexylbenzene is a precursor to both phenol and cyclohexanone.<ref name="acs phenol">{{cite web |url=https://www.acs.org/content/acs/en/pressroom/cutting-edge-chemistry/what-s-new-in-phenol-production-.html |title=What's New in Phenol Production? |last=Plotkin |first=Jeffrey S. |publisher=American Chemical Society |date=2016-03-21 |access-date=2018-01-02 |archive-url=https://web.archive.org/web/20191027122212/https://www.acs.org/content/acs/en/pressroom/cutting-edge-chemistry/what-s-new-in-phenol-production-.html |archive-date=2019-10-27 |url-status=dead }}</ref>

Hydration of cyclohexene gives [[cyclohexanol]], which can be [[dehydrogenation|dehydrogenated]] to give [[cyclohexanone]], a precursor to [[caprolactam]].<ref name=Ullmann>{{Ullmann|first1=Michael T.|last1= Musser|title=Cyclohexanol and Cyclohexanone|year=2005|doi=10.1002/14356007.a08_217}}</ref>

The [[oxidative cleavage]] of cyclohexene gives [[adipic acid]]. [[Hydrogen peroxide]] is used as the oxidant in the presence of a tungsten catalyst.<ref>{{cite journal |title= Green Chemistry in the Organic Teaching Laboratory: An Environmentally Benign Synthesis of Adipic Acid |first1= Scott M. |last1= Reed |first2= James E. |last2= Hutchison |journal= J. Chem. Educ. |year= 2000 |volume= 77 |issue= 12 |pages= 1627–1629 |doi= 10.1021/ed077p1627|bibcode= 2000JChEd..77.1627R }}</ref> 

[[1,5-Hexadiene]] is produced by [[ethenolysis]] of cyclohexene. Bromination gives 1,2-dibromocyclohexane.<ref>{{cite journal |doi=10.15227/orgsyn.012.0026|title=1,2-Dibromocyclohexane|journal=Organic Syntheses|year=1932|volume=12|page=26|author=H. R. Snyder, L. A. Brooks}}</ref>

== Structure ==
Cyclohexene is most stable in a half-chair [[conformational isomerism|conformation]],<ref>{{cite journal |title= Conformational preferences and interconversion barriers in cyclohexene and derivatives |first1= Frederick R. |last1= Jensen |first2= C. Hackett |last2= Bushweller |journal= J. Am. Chem. Soc. |year= 1969 |volume= 91 |issue= 21 |pages= 5774–5782 |doi= 10.1021/ja01049a013}}</ref> unlike the preference for a chair form of [[cyclohexane]]. One basis for the [[cyclohexane conformation]]al preference for a chair is that it allows each bond of the ring to adopt a [[staggered conformation]]. For cyclohexene, however, the alkene is planar, equivalent to an eclipsed conformation at that bond.

== See also ==
* [[Diels-Alder reaction]]
* [[Cyclohexa-1,3-diene]]
* [[Cyclohexa-1,4-diene]]

== References ==
{{Reflist}}

== External links ==
* {{ICSC|1054|10}}
* {{PGCH|0167}}
* [https://web.archive.org/web/20120328181429/http://hazard.com/msds/mf/baker/baker/files/c7073.htm Material Safety Data Sheet for cyclohexene]
* [https://web.archive.org/web/20071022034608/http://physchem.ox.ac.uk/MSDS/CY/cyclohexene.html Safety MSDS data]
* [https://web.archive.org/web/20070503012733/http://www.uni-regensburg.de/Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/D-Addit_ar-e.htm  Reaction of Cyclohexene with Bromine and Potassium Permanganate]
* [http://www.orgsyn.org/orgsyn/prep.asp?prep=cv1p0183 Cyclohexene synthesis]
* [http://www.inchem.org/documents/sids/sids/110838.pdf Data sheet at inchem.org]

{{cycloalkenes}}

[[Category:Cycloalkenes]]
[[Category:Hydrocarbon solvents]]