Orcinol is an organic compound with the formula CH₃C₆H₃(OH)₂. It occurs in many species of

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Roccella tinctoria'' and ''

Lecanora ''Lecanora'' is a genus of lichen commonly called rim lichens.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, Lichens in the genus '' Squamarina'' are also called rim lichens. Members of the genus have roughly c ...

''. Orcinol has been detected in the "toxic glue" of the ant species ''

Camponotus saundersi ''Colobopsis saundersi'', synonym ''Camponotus saundersi'', is a species of ant found in Malaysia and Brunei, belonging to the genus '' Colobopsis''. A worker can explode suicidally and aggressively as an ultimate act of defense, an ability it h ...

''. It is a colorless solid. It is related to

resorcinol Resorcinol (or resorcin) is an organic compound with the formula C6H4(OH)2. It is one of three isomeric benzenediols, the 1,3-isomer (or '' meta''-isomer). Resorcinol crystallizes from benzene as colorless needles that are readily soluble in ...

, 1,3-C₆H₄(OH)₂.

Synthesis and reactions

Orcinol was first prepared by dehydroacetic acid, a conversion that involved ring-opening of the pyrone to a triketone. This early experiment helped establish the rich condensation chemistry of

polyketide Polyketides are a class of natural products derived from a precursor molecule consisting of a chain of alternating ketone (or reduced forms of a ketone) and methylene groups: (-CO-CH2-). First studied in the early 20th century, discovery, biosynth ...

s. It can be obtained by fusing extract of

aloe ''Aloe'' (; also written ''Aloë'') is a genus containing over 650 species of flowering succulent plants.WFO (2022): Aloe L. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-4000001341. Accessed on: 06 Nov 2022 The most wi ...

s with

potash Potash () includes various mined and manufactured salts that contain potassium in water- soluble form.

, followed by acidification. It undergoes O-

methylation In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These ...

with dimethylsulfate. It is used in the production of the dye orcein and as a

reagent In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...

in some chemical tests for

pentose In chemistry, a pentose is a monosaccharide (simple sugar) with five carbon atoms. The chemical formula of many pentoses is , and their molecular weight is 150.13 g/mol.Bial's Test. It may be synthesized from

toluene Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon. It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) ...

; more interesting is its production when acetone dicarboxylic ester is condensed with the aid of

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

. It crystallizes in colorless prisms with one molecule of water, which redden on exposure to air.

Ferric chloride Iron(III) chloride is the inorganic compound with the formula . Also called ferric chloride, it is a common compound of iron in the +3 oxidation state. The anhydrous compound is a crystalline solid with a melting point of 307.6 °C. The col ...

gives a bluish-violet coloration with the aqueous solution. Unlike

it does not give a

fluorescein Fluorescein is an organic compound and dye based on the xanthene tricyclic structural motif, formally belonging to triarylmethine dyes family. It is available as a dark orange/red powder slightly soluble in water and alcohol. It is widely used ...

with

phthalic anhydride Phthalic anhydride is the organic compound with the formula C6H4(CO)2O. It is the anhydride of phthalic acid. Phthalic anhydride is a principal commercial form of phthalic acid. It was the first anhydride of a dicarboxylic acid to be used commer ...

. Oxidation of the ammoniacal solution gives orcein, C₂₈H₂₄N₂O₇, the chief constituent of the

natural dye Natural dyes are dyes or colorants derived from plants, invertebrates, or minerals. The majority of natural dyes are vegetable dyes from plant sources— roots, berries, bark, leaves, and wood—and other biological sources such as fungi. Ar ...

archil Archil may refer to: People Archil, a historical Georgian male given name (including people with that name) Georgian Royalty *5th-century Archil of Iberia *8th century prince and martyr Archil of Kakheti *16th-century Archil, Prince of Mukhra ...

. 4-Methylcatechol is an

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Is ...

, found as its methyl ether ( creosol) in

beech Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engl ...

-wood tar. : Orcin Merck 820933

Production from shale oil

Orcinol is also found in

shale oil Shale oil is an unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. These processes convert the organic matter within the rock ( kerogen) into synthetic oil and gas. The resulting ...

produced from Kukersite oil shale. It is the main water-soluble phenol in the oil, and has been extracted and refined industrially by

Viru Keemia Grupp Viru Keemia Grupp (VKG) is an Estonian holding group of oil shale industry, power generation, and public utility companies. History After Estonia gained independence, the state owned oil shale enterprise, Riigi Põlevkivitööstus ( en, Eston ...

References

* {{1911, wstitle=Orcin, volume=20, page=173 Alkylresorcinols

Synthesis and reactions

Production from shale oil

See also

References