Cyclohexene is a hydrocarbon with the formula (CH2)4C2H2. It is a cycloalkene. At room temperature, cyclohexene is a colorless liquid with a sharp odor. Among its uses, it is an intermediate in the commercial synthesis of nylon.[3]

Production and uses

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

Reactions and uses

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]

1,5-Hexadiene is produced by ethenolysis of cyclohexene. Bromination gives 1,2-dibromocyclohexane.[10]

Structure

Cyclohexene is most stable in a half-chair conformation,[11] 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.

See also

References

  1. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0167". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ "Cyclohexene". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  3. ^ Xie, Feng; Chen, Lihang; Cedeño Morales, Eder Moisés; Ullah, Saif; Fu, Yiwen; Thonhauser, Timo; Tan, Kui; Bao, Zongbi; Li, Jing (2024). "Complete separation of benzene-cyclohexene-cyclohexane mixtures via temperature-dependent molecular sieving by a flexible chain-like coordination polymer". Nature Communications. 15 (1): 2240. Bibcode:2024NatCo..15.2240X. doi:10.1038/s41467-024-46556-6. PMC 10933443. PMID 38472202.
  4. ^ US 9771313, Narisawa, Naoki & Tanaka, Katsutoshi, "Cyclohexanol, method for producing cyclohexanol, and method for producing adipic acid", published 26 Sep 2017 
  5. ^ G. H. Coleman, H. F. Johnstone (1925). "Cyclohexene". Organic Syntheses. 5: 33. doi:10.15227/orgsyn.005.0033.
  6. ^ B. B. Corson, V. N. Ipatieff (1939). "Cyclohexylbenzene". Organic Syntheses. 19: 36. doi:10.15227/orgsyn.019.0036.
  7. ^ Plotkin, Jeffrey S. (2016-03-21). "What's New in Phenol Production?". American Chemical Society. Archived from the original on 2019-10-27. Retrieved 2018-01-02.
  8. ^ Musser, Michael T. (2005). "Cyclohexanol and Cyclohexanone". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a08_217. ISBN 978-3-527-30673-2.
  9. ^ Reed, Scott M.; Hutchison, James E. (2000). "Green Chemistry in the Organic Teaching Laboratory: An Environmentally Benign Synthesis of Adipic Acid". J. Chem. Educ. 77 (12): 1627–1629. Bibcode:2000JChEd..77.1627R. doi:10.1021/ed077p1627.
  10. ^ H. R. Snyder, L. A. Brooks (1932). "1,2-Dibromocyclohexane". Organic Syntheses. 12: 26. doi:10.15227/orgsyn.012.0026.
  11. ^ Jensen, Frederick R.; Bushweller, C. Hackett (1969). "Conformational preferences and interconversion barriers in cyclohexene and derivatives". J. Am. Chem. Soc. 91 (21): 5774–5782. doi:10.1021/ja01049a013.
Allikas: https://en.wikipedia.org/wiki/Cyclohexene
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