1,5-Hexadiene
{{Chembox
| ImageFile = 1,5-hexadienestick.png
| ImageSize =
| ImageAlt =
| PIN = Hexa-1,5-diene
| OtherNames = diallyl, biallyl, α,ω-Hexadiene
|Section1={{Chembox Identifiers
| CASNo = 592-42-7
| PubChem = 11598
| EC_number = 209-754-7
| UNII = 4MTZ4764FI
| ChemSpiderID = 11110
| InChI=1S/C6H10/c1-3-5-6-4-2/h3-4H,1-2,5-6H2
| InChIKey = PYGSKMBEVAICCR-UHFFFAOYSA-N
| SMILES = C=CCCC=C}}
|Section2={{Chembox Properties
| C=6|H=10
| MolarMass =
| Appearance = colorless liquid
| Density =
| MeltingPt =
| BoilingPtC = 59–60
| Solubility = }}
|Section3={{Chembox Hazards
| GHSPictograms = {{GHS02}}{{GHS07}}{{GHS08}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|225|302|305|315|319|335|336}}
| PPhrases = {{P-phrases|210|233|240|241|242|243|261|264|271|280|301+310|302+352|303+361+353|304+340|305+351+338|312|321|331|332+313|337+313|362|370+378|403+233|403+235|405|501}}
| MainHazards =
| FlashPt =
| AutoignitionPt = }}
}}
1,5-Hexadiene is the organic compound with the formula (CH{{sub|2}}){{sub|2}}(CH=CH{{sub|2}}){{sub|2}}. It is a colorless, volatile liquid. It is used as a crosslinking agent and precursor to a variety of other compounds.
Synthesis
1,5-Hexadiene is produced commercially by the ethenolysis of 1,5-cyclooctadiene:{{cite encyclopedia|title=Metathesis|encyclopedia=Kirk-Othmer Encyclopedia of Chemical Technology|author=Lionel Delaude|author2=Alfred F. Noels|year=2005| doi=10.1002/0471238961.metanoel.a01|place=Weinheim|publisher=Wiley-VCH|isbn=9780471484943 }}
:(CH{{sub|2}}CH=CHCH{{sub|2}}){{sub|2}} + 2 CH{{sub|2}}=CH{{sub|2}} → 2 (CH{{sub|2}}){{sub|2}}CH=CH{{sub|2}}
The catalyst is derived from rhenium heptoxide on alumina.
A laboratory-scale preparation involves reductive coupling of allyl chloride using magnesium:{{cite journal|title=Biallyl|author=Amos Turk|author2=Henry Chanan|journal=Org. Synth.|year=1947|volume=27|page=7|doi=10.15227/orgsyn.027.0007}}
:{{chem2|2 ClCH2CH\dCH2 + Mg → (CH2CH\dCH2)2 + MgCl2}}