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 ac ...

analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is encoded in a continuous variable ** Analog device, an apparatus that operates on analog signals *** Analog electronics, circuits which use analog ...

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 react ...

. 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 Tetrahydrofuran (THF), or oxolane, is an organic compound with the formula (CH2)4O. The compound is classified as heterocyclic compound, specifically a cyclic ether. It is a colorless, water- miscible organic liquid with low viscosity. It is ...

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 ligand is an ion or molecule ( functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's elec ...

in coordination chemistry, an example being the complex

chloro(tetrahydrothiophene)gold(I) Chloro(tetrahydrothiophene)gold(I), abbreviated (tht)AuCl, is a coordination complex of gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that oc ...

. Oxidation of THT gives the sulfone sulfolane, 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 vi ...

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 ...

'' Mill. (salad rocket) while monocyclic substituted tetrahydrothiophenes have been isolated from '' Allium fistulosum'' 'Kujou', '' Allium sativum'' (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), and '' Salacia prinoides.'' Albomycins are a group of tetrahydrothiophene-ring containing antibiotics from streptomyces while biotin and

neothiobinupharidine Neothiobinupharidine is a dimeric thiaspirane alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even wea ...

(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, a ...

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 carbo ...

, 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