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

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

This can also be produced by the hydrolysis of either everninic acid orramalic 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.

Biosynthesis of orsellinic acid from polyketides

References

  1. ^ 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.
  2. ^ 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.
  3. ^ a b Merck Index (11th ed.). p. 1179-1180. 7009. o-Orsellinic acid.