Cyclohexene

Cyclohexene is produced by the partial hydrogenation of benzene, a process developed by the Asahi Chemical company.^[4] 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 of cyclohexanol.^[5]

C₆H₁₁OH → C₆H₁₀ + H₂O

Benzene is converted to cyclohexylbenzene by acid-catalyzed alkylation with cyclohexene.^[6] Cyclohexylbenzene is a precursor to both phenol and cyclohexanone.^[7]

Hydration of cyclohexene gives cyclohexanol, which can be dehydrogenated to give cyclohexanone, a precursor to caprolactam.^[8]

The oxidative cleavage of cyclohexene gives adipic acid. Hydrogen peroxide is used as the oxidant in the presence of a tungsten catalyst.^[9]

1,7-Octadiene is produced by ethenolysis of cyclohexene.^[10] Bromination gives 1,2-dibromocyclohexane.^[11]

Cyclohexene is most stable in a half-chair conformation,^[12] unlike the preference for a chair form of cyclohexane. One basis for the cyclohexane conformational 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.

• Diels-Alder reaction
• Cyclohexa-1,3-diene
• Cyclohexa-1,4-diene