Tetrahydrothiophene is an organosulfur compound with the formula (CH₂)₄S. The molecule consists of a five-membered saturated ring with four methylene groups and a sulfur atom. It is the

saturated Saturation, saturated, unsaturation or unsaturated may refer to: Chemistry * Saturation, a property of organic compounds referring to carbon-carbon bonds **Saturated and unsaturated compounds **Degree of unsaturation **Saturated fat or fatty acid ...

analog of

thiophene Thiophene is a heterocyclic compound with the formula C4H4S. Consisting of a planar five-membered ring, it is aromatic as indicated by its extensive substitution reactions. It is a colorless liquid with a benzene-like odor. In most of its reacti ...

. It is a volatile, colorless liquid with an intensely unpleasant odor. It is also known as thiophane, thiolane, or THT. While THT is not particularly common, the vitamin biotin is essential for life in aerobic organisms.

Synthesis and reactions

Tetrahydrothiophene is prepared by the reaction of tetrahydrofuran with hydrogen sulfide. This vapor-phase reaction is catalyzed by alumina and other heterogenous acid catalysts. This compound is a ligand in

coordination chemistry A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...

, an example being the complex chloro(tetrahydrothiophene)gold(I). Oxidation of THT gives the sulfone

sulfolane Sulfolane (also ''tetramethylene sulfone'', systematic name: 1λ6-thiolane-1,1-dione) is an organosulfur compound, formally a cyclic sulfone, with the formula (CH2)4SO2. It is a colorless liquid commonly used in the chemical industry as a solvent ...

, which is of interest as a polar, odorless solvent: : Sulfolane is, however, more conventionally prepared from

butadiene 1,3-Butadiene () is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a precursor to synthetic rubber. The molecule can be viewed as the union of two v ...

Natural occurrence

Both unsubstituted and substituted tetrahydrothiophenes are reported to occur in nature. For example, tetrahydrothiophene occurs as a volatile from ''

Eruca sativa Arugula (American English) or rocket (Commonwealth English) (''Eruca vesicaria''; syns. ''Eruca sativa'' Mill., ''E. vesicaria'' subsp. ''sativa'' (Miller) Thell., ''Brassica eruca'' L.) is an edible annual plant in the family Brassicaceae used a ...

'' Mill. (salad rocket) while monocyclic substituted tetrahydrothiophenes have been isolated from ''

Allium fistulosum ''Allium fistulosum'', the Welsh onion, also commonly called bunching onion, long green onion, Japanese bunching onion, and spring onion, is a species of perennial plant, often considered to be a kind of scallion. The species is very similar ...

'' 'Kujou', ''

Allium sativum Garlic (''Allium sativum'') is a species of bulbous flowering plant in the genus ''Allium''. Its close relatives include the onion, shallot, leek, chive, Welsh onion and Chinese onion. It is native to South Asia, Central Asia and northeastern ...

'' (garlic), ''

Allium cepa An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onion ...

'' (onion), ''

Allium schoenoprasum Chives, scientific name ''Allium schoenoprasum'', is a species of flowering plant in the family Amaryllidaceae that produces edible leaves and flowers. Their close relatives include the common onions, garlic, shallot, leek, scallion, an ...

'' (chives), and '' Salacia prinoides.''

Albomycin Albomycins are a group of naturally occurring antibiotics belonging to the class of sideromycins, which are "compounds composed of iron carriers called siderophores linked to antibiotic moieties". They are particularly effective against Gram-nega ...

s are a group of tetrahydrothiophene-ring containing antibiotics from

streptomyces ''Streptomyces'' is the largest genus of Actinomycetota and the type genus of the family Streptomycetaceae. Over 500 species of ''Streptomyces'' bacteria have been described. As with the other Actinomycetota, streptomycetes are gram-positiv ...

while

biotin Biotin (or vitamin B7) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name ''biotin'', bor ...

and neothiobinupharidine (and other

nuphar ''Nuphar'' is a genus of aquatic plants in the family Nymphaeaceae, with a temperate to subarctic Northern Hemisphere distribution. Common names include water-lily (Eurasian species; shared with many other genera in the same family), pond-lily, ...

alkaloids ), are examples of bicyclic and polycyclic tetrahydrothiophene-ring containing natural products, respectively.

Applications

Because of its smell, tetrahydrothiophene has been used as an

odorant An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently vol ...

in LPG, albeit no longer in North America. It is also used as an odorant for

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon di ...

, usually in mixtures containing ''tert''-butylthiol. Tetrahydrothiophene is a Lewis base classified as a soft base and its donor properties are discussed in the ECW model.

References

{{reflist Thiolanes Solvents Foul-smelling chemicals

Synthesis and reactions

Natural occurrence

Applications

See also

References