Orsellinic acid
Appearance
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Names | |||
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Preferred IUPAC name
2,4-Dihydroxy-6-methylbenzoic acid | |||
Identifiers | |||
3D model (JSmol)
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ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard | 100.115.964 | ||
KEGG | |||
PubChem CID
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UNII | |||
CompTox Dashboard (EPA)
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Properties | |||
C8H8O4 | |||
Molar mass | 168.148 g·mol−1 | ||
Melting point | 176 °C (349 °F; 449 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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Orsellinic acid, more specifically o-orsellinic acid, is a phenolic acid. It is of importance in the biochemistry of lichens, from which it can be extracted.[1] It is a common subunit of depsides.
Chemistry
[edit]It can be prepared by the oxidation of orsellaldehyde,[2] or through a Michael adduct:
![Ethyl acetoacetate condenses with ethyl crotonate to give ethyl dihydroorsellinate, followed by oxidation and hydrolysis](http://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/Synthesis_Orsellinic_acid_A.svg/476px-Synthesis_Orsellinic_acid_A.svg.png)
This can also be produced by the hydrolysis of either everninic acid or ramalic acid by boiling with barium hydroxide. When crystallized from acetone it forms crystalline needles with a melting point of 176 °C.[3] It also forms a crystalline hydrate with a melting point of 186-189 °C when crystallized from water.[3]
Orsellinic acid is biosynthesized by a polyketide pathway.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/44/Orsellins%C3%A4ure_is.svg/620px-Orsellins%C3%A4ure_is.svg.png)
References
[edit]- ^ Nolan, T. J.; Keane, J.; Davidson, V. E. (1940). "Chemical constituents of the lichen Parmelia latissima Fee". Scientific Proceedings of the Royal Dublin Society, Series A. 22: 237–239.
- ^ Kang, Ying; Mei, Yan; Du, Yuguo; Jin, Zhendong (2003). "Total Synthesis of the Highly Potent Anti-HIV Natural Product Daurichromenic Acid along with Its Two Chromane Derivatives, Rhododaurichromanic Acids A and B". Organic Letters. 5 (23): 4481–4484. doi:10.1021/ol030109m. PMID 14602030.
- ^ a b Merck Index (11th ed.). p. 1179-1180. 7009. o-Orsellinic acid.