Benzocyclobutadiene

Not to be confused with benzocyclobutene.

Benzocyclobutadiene is the simplest polycyclic hydrocarbon, being composed of an aromatic benzene ring fused to an anti-aromatic cyclobutadiene ring. It has chemical formula C₈H₆. Though the benzene ring is stabilized by aromaticity, the cyclobutadiene portion has a destabilizing effect. This results into it being a non-aromatic compound - neither behaving as aromatic nor an antiaromatic one.^[1] For this reason, benzocyclobutadiene will readily dimerize or polymerize and it reacts as a dienophile in Diels-Alder reactions.^[2]

Benzocyclobutadiene

Names
Preferred IUPAC name Bicyclo[4.2.0]octa-1,3,5,7-tetraene
Identifiers
CAS Number	4026-23-7 Y
3D model (JSmol)	Interactive image
ChemSpider	70373 Y
PubChem CID	77987
UNII	T7CEM83V4M Y
CompTox Dashboard (EPA)	DTXSID60193245
InChI InChI=1S/C8H6/c1-2-4-8-6-5-7(8)3-1/h1-6H Y Key: WHEATZOONURNGF-UHFFFAOYSA-N Y InChI=1/C8H6/c1-2-4-8-6-5-7(8)3-1/h1-6H Key: WHEATZOONURNGF-UHFFFAOYAK
SMILES C12=CC=CC=C1C=C2
Properties
Chemical formula	C8H6
Molar mass	102.136 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Benzocyclobutadiene is used in the production of the pharmaceutical drug naflocort.^{[citation needed]}

See also

• Pentalene

References

1. Observation of benzocyclobutadiene by flow nuclear magnetic resonance https://doi.org/10.1021/ja00168a059
2. Carey, Francis A.; Sundberg, Richard J. (1984). Advanced Organic Chemistry Part A Structure and Mechanisms (2nd ed.). New York, NY: Plenum Press. ISBN 0-306-41198-9.