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Benzopyran

From Wikipedia, the free encyclopedia
Benzopyran
Identifiers
3D model (JSmol)
109871
ChEBI
ChemSpider
UNII
  • InChI=1S/C9H7O/c1-2-6-9-8(4-1)5-3-7-10-9/h1-7H checkY
    Key: QZHPTGXQGDFGEN-UHFFFAOYSA-N checkY
  • c12ccccc1CC=CO2
Properties
C9H8O
Molar mass 132.162 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Benzopyran is a polycyclic organic compound that results from the fusion of a benzene ring to a heterocyclic pyran ring.

According to current IUPAC nomenclature, the name chromene used in previous recommendations is retained; however, systematic ‘benzo’ names, for example 2H-1-benzopyran, are preferred IUPAC names for chromene, isochromene, chromane, isochromane, and their chalcogen analogues.[1] There are two isomers of benzopyran that vary by the orientation of the fusion of the two rings compared to the oxygen, resulting in 1-benzopyran (chromene) and 2-benzopyran (isochromene)—the number denotes where the oxygen atom is located by standard naphthalene-like nomenclature.

Some benzopyrans have shown anticancerous activity in vitro.[2]

The radical form of benzopyran is paramagnetic. The unpaired electron is delocalized over the whole benzopyran molecule, rendering it less reactive than one would expect otherwise. A similar example is the cyclopentadienyl radical. Commonly, benzopyran is encountered in the reduced state, in which it is partially saturated with one hydrogen atom, introducing a tetrahedral CH2 group in the pyran ring. Therefore, there are many structural isomers owing to the multiple possible positions of the oxygen atom and the tetrahedral carbon atom:

Structural isomers of chromene

2H-chromene
(2H-1-benzopyran)

4H-chromene
(4H-1-benzopyran)
5H-chromene 7H-chromene
8aH-chromene
Structural isomers of isochromene

1H-isochromene
(1H-2-benzopyran)

3H-isochromene
(3H-2-benzopyran)

See also

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References

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  1. ^ "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. pp. P001–P004. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  2. ^ Stevenson, Alexander J; Ager, Eleanor I; Proctor, Martina A; Škalamera, Dubravka; Heaton, Andrew; Brown, David; Gabrielli, Brian G (2018). "Mechanism of action of the third generation benzopyrans and evaluation of their broad anti-cancer activity in vitro and in vivo". Scientific Reports. 8 (1): 5144. Bibcode:2018NatSR...8.5144S. doi:10.1038/s41598-018-22882-w. PMC 5865165. PMID 29572477.