{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 424960119 | ImageFile=Thietene.png | ImageSize=100 | PIN=2''H''-Thiete | OtherNames=1-Thiacyclobut-2-ene |Section1={{Chembox Identifiers | CASNo=503-31-1 | PubChem=3415867 | SMILES=C1C=CS1 | ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}} | ChemSpiderID = 2659702 | InChI = 1/C3H4S/c1-2-4-3-1/h1-2H,3H2 | InChIKey = HPINPCFOKNNWNW-UHFFFAOYAF | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/C3H4S/c1-2-4-3-1/h1-2H,3H2 | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = HPINPCFOKNNWNW-UHFFFAOYSA-N }} |Section2={{Chembox Properties | Formula=C<sub>3</sub>H<sub>4</sub>S | MolarMass=72.12886 | Appearance= | Density= | MeltingPt= | BoilingPt= | Solubility= }} }}

'''Thiete''' is a heterocyclic compound containing an unsaturated four-membered ring with three carbon atoms and one sulfur atom.<ref>{{cite journal |last= Leśniak |first=S |author2=Lewkowski, J |author3=Kudelska, W |author4= Zając, A | title =Thietanes and Thietes: Monocyclic |journal =Comprehensive Heterocyclic Chemistry III |year=2008 |volume=2 |issue=7 |pages=389–428 |doi=10.1016/B978-008044992-0.00207-8}}</ref><ref>{{cite journal |last=Block |first=E |title=Thietes and Derivatives |journal =Sci. Synth. |year=2007 |volume=33 |pages=187–202}}</ref><ref name=Encyc>{{Cite book|last1=Block|first1=Eric|title=Comprehensive Heterocyclic Chemistry II|last2=Wang|first2=Ming De|publisher=Elsevier|year=1996|isbn=978-0-08-096518-5|editor-last=Katritzky|editor-first=Alan R.|edition=2nd|volume=1B|pages=773&ndash;802|chapter=Thietanes and Thietes: Monocyclic|editor-last2=Rees|editor-first2=Charles W.|editor-last3=Scriven|editor-first3=Eric F. V.}}</ref> It is more commonly encountered not on its own, but in anellated derivatives, several of which have been synthesized. Thietes are generally not very stable.<ref>{{cite journal |last=Dittmer|first=DC|author2=Davis, FA| title=Evidence for a Thiete (Thiacyclobutene) |journal =J. Am. Chem. Soc.|year=1965 |volume=87|issue=9 |pages=2064–2065 |doi=10.1021/ja01087a048|bibcode=1965JAChS..87.2064D }}</ref>

== Structure == Thiete is a valence isomer of the compound thioacrolein (CH<sub>2</sub>=CHCH=S) and undergoes ring opening to it when heated at temperatures below 400{{Nbsp}}°C.<ref name=Encyc/>{{rp|780}} Thiete has been shown to be planar, with a C-S-C angle of 76.8 degrees.<ref>{{cite journal |last=Rodler |first=M |author2=Bauder, A |title =Microwave spectrum, dipole moment and molecular structure of 1,2-dithiete|journal =Chemical Physics Letters|year=1985 |volume=114 |issue=5–6 |pages=575–578 |doi=10.1016/0009-2614(85)85145-9|bibcode=1985CPL...114..575R }}</ref>

In principle, deprotonation should give a cyclic, planar anion with 6 π electrons, satisfying the Hückel criteria for aromaticity. Computer simulations in 1965 suggested that any aromatic stabilization was small, and other known approximation errors likely increased the instability. Certainly, attempts at deprotonation give only an uncharacterized mixture of decomposition products or nucleophilic substitution, even with relatively hindered bases.<ref name=Rev>{{cite book|pp=513&ndash;514, 522&ndash;523|doi=10.1002/9780470187203|title=Small Ring Heterocycles|volume=3|chapter=Four-membered sulfur heterocycles|first1=D. C.|last1=Dittmer|first2=T. C.|last2=Sedergran|series=Chemistry of Heterocyclic Compounds|year=1985|publisher=Wiley|isbn=9780471056249}}</ref>

==Derivatives== Benzothietes are thietes annulated to benzo group. Such species are prepared by flash vacuum pyrolysis of 2-mercaptobenzyl alcohols. They are precursors to other S-heterocycles.<ref>Herbert Meier, Axel Mayer, Dieter Gröschl "Benzothietes—versatile Synthons For The Preparation Of Heterocycles" Sulfur Reports, 1994, volume 16, 23-56, {{doi|10.1080/01961779408048965}}</ref>

Thiete 1,1-dioxides are sulfones, the parent being C<sub>3</sub>H<sub>4</sub>SO<sub>2</sub>. They are more stable than the parent thietes.<ref>Thomas C. Sedergran and Donald C. Dittmer "Thiete 1,1-dioxide and Chlorothiete 1,1-dioxide" Org. Synth. 1984, vol. 62, 210.{{doi|10.15227/orgsyn.062.0210}}</ref> Substituted thiete-1,1-dioxides can be prepared through oxidation of thietes, elimination of thietane dioxides, or [2+2] cycloaddition of sulfenes and ynamines.<ref name=Rev/>{{rp|pp=531-535}}

== See also ==

* Dithiete - analogue with two sulfur atoms

== References == {{Reflist}}

Category:Sulfur heterocycles Category:Four-membered rings