dithietane

1,2-dithietanes, 4-membered rings where the two sulfur atoms are adjacent, are very rare. The first stable 1,2-dithietane to be reported was the dithiatopazine, formed by intramolecular photodimerization of a dithiocarbonyl compound.{{cite journal |last=Nicolaou |first=KC |author2=Hwang, CK |author3=Duggan, ME |author4= Carroll, PJ |title=Dithiatopazine. The first stable 1,2-dithietane |journal =J. Am. Chem. Soc.|year=1987|volume=109|issue=12|pages=3801–3802|doi=10.1021/ja00246a059}} File:Dithiatopazine.svg

1,2-Dithietanes are to be distinguished from 1,2-dithietes, containing two adjacent sulfur atoms and two sp²-hybridized carbon centers.

File:Trans-3,4-diethyl-1,2-dithietane 1,1-dioxide.svg

A stable 1,2-dithietane derivative is trans-3,4-diethyl-1,2-dithietane 1,1-dioxide, formed by the spontaneous dimerization of the lachrymatory agent syn-propanethial-S-oxide, found in onion.{{cite journal |last=Block |first=E |author2=Bazzi, AA |author3=Revelle, LK |title=The chemistry of sulfines. 6. Dimer of the onion lachrymatory factor: the first stable 1,2-dithietane derivative |journal =J. Am. Chem. Soc.|year=1980|volume=102|issue=7|pages=2490–2491|doi=10.1021/ja00527a074}}

In 1,3-dithietanes, the sulfur atoms are non-adjacent.{{cite journal |last=Luh |first=TY |author2=Leung, MK| title =Product Subclass 2: 1,3-Dithietanes |journal =Sci. Synth. |year=2007 |volume=30 |pages=203–219}} 1,3-Dithietane itself, a colorless, easily sublimed, crystalline, unpleasant-smelling solid with melting point 105-106 °C, was first prepared in 1976 by reaction of bis(chloromethyl) sulfoxide with sodium sulfide followed by THF-borane reduction of the first formed 1,3-dithietane 1-oxide, as shown in the scheme below.{{cite journal |last=Block |first=E |author2=Corey, ER |author3=Penn, RE |author4=Renken, TL |author5= Sherwin, PF |title=1,3-Dithietane |journal=J. Am. Chem. Soc.|year=1976|volume=98|issue=18|pages=5715–5717|doi=10.1021/ja00434a061}}{{cite journal |last=Block |first=E |author2=Corey, ER |author3=Penn, RE |author4=Renken, TL |author5=Sherwin, PF |author6=Bock, H |author7=Hirabayashi, T |author8=Mohmand, S |author9= Solouki, B |title=Synthesis and Thermal Decomposition of 1,3-Dithietane and its S-Oxides |journal=J. Am. Chem. Soc.|year=1982|volume=104|issue=11|pages=3119–3130|doi=10.1021/ja00375a030}} Carbon-substituted 1,3-dithietanes are well known, with the first examples being described as early as 1872. Examples include 2,2,4,4-tetrachloro-1,3-dithietane, the photochemically-formed dimer of thiophosgene, and tetrakis(trifluoromethyl)-1,3-dithietane, [(CF₃)₂CS]₂.{{OrgSynth | author = Van Der Puy, M. | author2 = Anello, L. G. | title= Hexafluoroacetone | collvol = 7 | collvolpages = 251. | year =1990 |prep = CV7P0251}}

File:Synthesis of 1,3-dithietane.svg

Oxidized forms of 1,3-dithietane are well known, although they are often not prepared from the dithietane. Examples include the so-called zwiebelanes (2,3-dimethyl-5,6-dithiabicyclo[2.1.1]hexane S-oxides) from onion volatiles{{cite journal |last=Block |first=E |author2=Thiruvazhi, M |author3=Toscano, PJ |author4=Bayer, T |author5=Grisoni, S |author6= Zhao, SH |title=Allium Chemistry: Structure, Synthesis, Natural Occurrence in Onion (Allium cepa), and Reactions of 2,3-Dimethyl-5,6-dithiabicyclo[2.1.1]hexane S-Oxides |journal =J. Am. Chem. Soc.|year=1996|volume=118|issue=12|pages=2790–2798|doi=10.1021/ja951134t}} and 1,3-dithietane 1,1,3,3-tetraoxide, the so-called sulfene dimer.{{cite journal |last=Opitz|first=G |author2=Mohl, HR|title=Disulfene |journal =Angew. Chem. Int. Ed.|year=1969|volume=8|issue=1|pages=73|doi=10.1002/anie.196900731}}

File:1,3-Dithietanes.svg dimer, 2,2,4,4-tetrachloro-1,3-dithietane; center: a zwiebelane, found in onion volatiles; right: sulfene dimer]]

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