A dithiane is a heterocyclic compound composed of a

cyclohexane Cyclohexane is a cycloalkane with the molecular formula . Cyclohexane is non-polar. Cyclohexane is a colorless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products (in which it is sometimes used). Cyclohex ...

core structure wherein two

methylene bridge In organic chemistry, a methylene bridge, methylene spacer, or methanediyl group is any part of a molecule with formula ; namely, a carbon atom bound to two hydrogen atoms and connected by single bonds to two other distinct atoms in the rest of ...

s (-- units) are replaced by

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...

centres. The three isomeric parent heterocycles are 1,2-dithiane, 1,3-dithiane and 1,4-dithiane.

1,3-Dithianes

1,3-Dithianes are

protecting group A protecting group or protective group is introduced into a molecule by chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction. It plays an important role in multistep organic synthesis. In man ...

of some

carbonyl In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. A compound containin ...

-containing compounds due to their inertness to many conditions. They form by treatment of the carbonyl compound with

1,3-propanedithiol 1,3-Propanedithiol is the chemical compound with the formula HSCH2CH2CH2SH. This dithiol is a useful reagent in organic synthesis. This liquid, which is readily available commercially, has an intense stench. Use in organic synthesis 1,3-Propan ...

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 also employed in

umpolung In organic chemistry, umpolung () or polarity inversion is the chemical modification of a functional group with the aim of the reversal of polarity of that group. This modification allows secondary reactions of this functional group that would oth ...

reactions, such as the

Corey–Seebach reaction The Corey–Seebach reaction, or Seebach Umpolung is a name reaction of organic chemistry that allows for acylation by converting aldehydes into lithiated 1,3-dithianes. The lithiated 1,3-dithianes serves as an acyl anion equivalent, undergoing a ...

:T. W. Green, P. G. M. Wuts, "Protective Groups in Organic Synthesis" Wiley-Interscience, New York, 1999. . : Dithiane chemistry

Typically, in

organic synthesis Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one o ...

, ketones and aldehydes are protected as their

dioxolane Dioxolane is a heterocyclic acetal with the chemical formula (CH2)2O2CH2. It is related to tetrahydrofuran by interchange of one oxygen for a CH2 group. The corresponding saturated 6-membered C4O2 rings are called dioxanes. The isomeric 1,2-dioxo ...

s instead of dithianes.

References

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External links

Corey-Seebach Reaction