Oxepin is an oxygen-containing heterocycle consisting of a seven-membered ring with three double bonds. The parent C6H6O exists as an equilibrium mixture with benzene oxide. The oxepin–benzene oxide equilibrium is affected by the ring substituents.[1] A related dimethyl derivative exists mainly as the oxepin isomer, an orange liquid.[2]

Skeletal formula of oxepin
Ball-and-stick model of the oxepin molecule
IUPAC name
Other names
Benzene oxide
3D model (JSmol)
Molar mass 94.11 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Formation and selected reactions of benzene oxide.

Oxepin is an intermediate in the oxidation of benzene by the cytochrome P450.[3] Other arene oxides are metabolites of the parent arene.


  1. ^ E. Vogel, H. Günther (1967). "Benzene Oxide-Oxepin Valence Tautomerism". Angewandte Chemie International Edition in English. 6 (5): 385–401. doi:10.1002/anie.196703851.
  2. ^ L. A. Paquette and J. H. Barrett (1969). "2,7-Dimethyloxepin". Org. Synth. 49: 62. doi:10.15227/orgsyn.049.0062.CS1 maint: uses authors parameter (link)
  3. ^ R. Snyder, G. Witz, and B. D. Goldstein (1993). "The Toxicology of Benzene". Environmental Health Perspectives. 100: 293–306. doi:10.1289/ehp.93100293. JSTOR 3431535. PMC 1519582. PMID 8354177.CS1 maint: multiple names: authors list (link)