Chemistry:Dithiane

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Dithianes
DithianeOverviewBW.svg
1,2-dithiane (left), 1,3-dithiane and 1,4-dithiane (right)
Names
Other names
Dithiacyclohexanes
Identifiers
3D model (JSmol)
ChemSpider
Properties
C4H8S2
Molar mass 120.23 g·mol−1
Melting point 32.5 °C (90.5 °F; 305.6 K) other isomers: 54 (1,3), 112.3 (1,4)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

A dithiane is a heterocyclic compound composed of a cyclohexane core structure wherein two methylene bridges (-CH2- units) are replaced by sulfur. The three isomeric parent heterocycles are 1,2-dithiane, 1,3-dithiane and 1,4-dithiane. They are all colorless solids.

Space filling models of 1,2-dithiane (left), 1,3-dithiane and 1,4-dithiane (right)

1,2-Dithianes

1,2-Dithiane is an organosulfur compound with the formula S
2
C
4
H
8
. It is one of three isomers of the formula (CH
2
)
4
S
2
. The 1,2-isomer, a disulfide, arises by the oxidation of 1,4-butanedithiol.

1,3-Dithianes

1,3-Dithiane is an organosulfur compound with the formula CH
2
S
2
C
3
H
6
. It is one of three isomers of the formula (CH
2
)
4
S
2
. The 1,3-isomer arises by the reaction of 1,3-propanedithiol with formaldehyde.[1]

1,3-Dithianes are sometimes used as protecting group of carbonyl-containing compounds. They form by treatment of the carbonyl compound with 1,3-propanedithiol under conditions that remove water from the system. The protecting group can be removed with mercuric reagents, a process that exploits the high affinity of Hg(II) for thiolates. 1,3-Dithianes are more importantly employed in umpolung reactions, such as the Corey–Seebach reaction:[2]

1,4-Dithianes

1,4-Dithiane is an organosulfur compound with the formula (SC
2
H
4
)
2
. It is one of three isomers of the formula (CH
2
)
4
S
2
. The 1,4-isomer, a bisthioether, arises by the alkylation of 1,2-ethanedithiol with 1,2-dibromoethane. It has no applications but traces occurs as a product of degradations, e.g., cooking[3] coal pyrolysis.[4]

References

  1. Corey, E. J.; Seebach, D (1970). "1,3-Dithiane". Organic Syntheses 50: 72. doi:10.15227/orgsyn.050.0072. 
  2. Wuts, P. G. M.; Greene, T.W. (2006). Greene's Protective Groups in Organic Synthesis. NY: J. Wiley. doi:10.1002/0470053488. ISBN 9780470053485. 
  3. Garbusov, V.; Rehfeld, G.; Wölm, G.; Golovnja, R. V.; Rothe, M. (1976). "Volatile sulfur compounds contributing to meat flavour. Part. I. Components identified in boiled meat". Molecular Nutrition & Food Research 20 (3): 235–241. doi:10.1002/food.19760200302. 
  4. Calkins, William H. (1987). "Investigation of organic sulfur-containing structures in coal by flash pyrolysis experiments". Energy Fuels 1 (1): 59–64. doi:10.1021/ef00001a011. 

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