4-Vinylphenol

4-Vinylphenol is an organic compound with the formula C2H3C6H4OH. It is the most studied of the three isomeric vinylphenols. It is a white volatile solid.

4-Vinylphenol
Names
Preferred IUPAC name
4-Ethenylphenol
Other names
p-Vinylphenol
p-Hydroxystyrene
4-VP
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.018.276
UNII
  • InChI=1S/C8H8O/c1-2-7-3-5-8(9)6-4-7/h2-6,9H,1H2 ☒N
    Key: FUGYGGDSWSUORM-UHFFFAOYSA-N ☒N
  • InChI=1/C8H8O/c1-2-7-3-5-8(9)6-4-7/h2-6,9H,1H2
    Key: FUGYGGDSWSUORM-UHFFFAOYAQ
  • C=CC1=CC=C(C=C1)O
Properties
C8H8O
Molar mass 120.15 g/mol
Appearance white sublimable solid
Melting point 73.5 °C (164.3 °F; 346.6 K)
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

Production

Upon contact with iron oxide at 500 °C, 4-ethylphenol undergoes dehydrogenation to give 4-vinyllphenol:[1]

C2H5C6H4OH → C2H3C6H4OH + H2

Natural occurrence

It is found in wine and beer. It is produced by the spoilage yeast Brettanomyces. When it reaches concentrations greater than the sensory threshold, it can give the wine aromas described as barnyard, medicinal, band-aids, and mousy. In wine, 4-vinylphenol can react with other molecules, such as anthocyanidins, to produce new chemical compounds.[2] In white wines vinylphenols are dominant (4-vinylphenol 70-1 150 μg/L, 4-vinylguaiacol 10-490 μg/L) whereas, in red wines, it is the corresponding ethyl phenols.[3]

Biosynthesis
The conversion of p-coumaric acid to 4-ethylphenol by Brettanomyces via 4-vinylphenol

The enzyme cinnamate decarboxylase converts p-coumaric acid to 4-vinylphenol.[4][5] 4-Vinylphenol is further reduced to 4-ethylphenol by the enzyme vinyl phenol reductase. Coumaric acid is sometimes added to microbiological media, enabling the positive identification of Brettanomyces by smell.

See also

References
  1. Fiege, Helmut; Voges, Heinz-Werner; Hamamoto, Toshikazu; Umemura, Sumio; Iwata, Tadao; Miki, Hisaya; Fujita, Yasuhiro; Buysch, Hans-Josef; Garbe (2000). "Phenol Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_313.
  2. Structure of new anthocyanin-derived wine pigments. Hélène Fulcrand, Paulo-Jorge Cameira dos Santos, Pascale Sarni-Manchado, Véronique Cheynier and Jean Favre-Bonvin, J. Chem. Soc., Perkin Trans. 1, 1996, pages 735-739, doi:10.1039/P19960000735
  3. Flüchtige phenolische Verbindungen in Wein = Volatil phenolic compounds of wine. Rapp A. and Versini G., Deutsche Lebensmittel-Rundschau, 1996, vol. 92, no2, pages 42-48, INIST:2990913 (German)
  4. Chatonnet, Pascal; Dubourdie, Denis; Boidron, Jean-Noël; Pons, Monique (1992). "The origin of ethylphenols in wines". Journal of the Science of Food and Agriculture. 60 (2): 165–178. doi:10.1002/jsfa.2740600205.
  5. Brettanomyces Monitoring by Analysis of 4-ethylphenol and 4-ethylguaiacol Archived 2008-02-19 at the Wayback Machine at etslabs.com
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