Orcinol is a natural phenol

Natural phenol

Natural phenols, bioavailable phenols, plant phenolics, low molecular weight phenols or phenoloids are a class of natural products. They are small molecules containing one or more phenolic group. These molecules are smaller in size than polyphenols, containing less than 12 phenolic groups...

ic organic compound

Organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...

 that occurs in many species of lichen

Lichen

Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...

s including Rocella tinctoria and Lecanora

Lecanora

Lecanora is a genus of lichen belonging to the suborder Lecanorineae.-Historical Mention:Lecanora Tartarea was probably the Viking dye-moss from which the English word litmus derives because it is commonly found in Norway and Sweden.-External links:*...

. It can be formed by fusing extract of aloe

Aloe

Aloe , also Aloë, is a genus containing about 500 species of flowering succulent plants. The most common and well known of these is Aloe vera, or "true aloe"....

s with potash

Potash

Potash is the common name for various mined and manufactured salts that contain potassium in water-soluble form. In some rare cases, potash can be formed with traces of organic materials such as plant remains, and this was the major historical source for it before the industrial era...

.

It is used in the production of the dye orcein

Orcein

Orcein, also archil, orchil, lacmus, Citrus Red 2, and C.I. Natural Red 28, are names for dyes extracted from several species of lichen, commonly known as "orchella weeds", found in various parts of the world. A major source is the archil lichen, Roccella tinctoria. Orcinol is extracted from such...

 and as a reagent

Reagent

A reagent is a "substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs." Although the terms reactant and reagent are often used interchangeably, a reactant is less specifically a "substance that is consumed in the course of...

 in some chemical tests for pentose

Pentose

A pentose is a monosaccharide with five carbon atoms. Pentoses are organized into two groups. Aldopentoses have an aldehyde functional group at position 1...

s, such as Bial's Test

Bial's test

Bial's test is a chemical test for the presence of pentoses. The components include orcinol, hydrochloric acid, and ferric chloride. In the presence of a pentose, the pentose will be dehydrated to form furfural. The solution will turn bluish and a precipitate may form...

. It may be synthesized from toluene

Toluene

Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...

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

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

. It crystallizes in colorless prisms with one molecule of water, which redden on exposure to air. Ferric chloride gives a bluish-violet coloration with the aqueous solution. Unlike resorcinol

Resorcinol

Resorcinol is a dihydroxy benzene. It is the 1,3-isomer of benzenediol with the formula C6H42.-Nomenclature:Benzene-1,3-diol is the name recommended by the International Union of Pure and Applied Chemistry in its 1993 Recommendations for the Nomenclature of Organic Chemistry.-Production:It is...

 it does not give a fluorescein

Fluorescein

Fluorescein is a synthetic organic compound available as a dark orange/red powder soluble in water and alcohol. It is widely used as a fluorescent tracer for many applications....

 with phthalic anhydride

Phthalic anhydride

Phthalic anhydride is the organic compound with the formula C6H42O. It is the anhydride of phthalic acid. This colourless solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2002, approximately 4.6 billion kilograms were...

. Oxidation of the ammoniacal solution gives orcein

Orcein

Orcein, also archil, orchil, lacmus, Citrus Red 2, and C.I. Natural Red 28, are names for dyes extracted from several species of lichen, commonly known as "orchella weeds", found in various parts of the world. A major source is the archil lichen, Roccella tinctoria. Orcinol is extracted from such...

, C₂₈H₂₄N₂O₇, the chief constituent of the natural dye

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 organic sources such as fungi and lichens....

 archil. Homo-pyrocatechin is an isomer

Isomer

In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...

 (CH1: OH: OH= 1 3 :4), found as its methyl ether (creosol

Creosol

Creosol is an ingredient of creosote. Compared with phenol, creosol is a less toxic disinfectant.-Sources :* Coal tar creosote* Wood creosote* Reduction product of vanillin using zinc powder in strong hydrochloric acid...

) in beech

Beech

Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...

-wood tar.