1,3-Propanedithiol
Encyclopedia
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.
of aldehyde
s and ketone
s via their reversible formation of dithiane
s. A prototypical reaction
is its formation of 1,3-dithiane from formaldehyde
. The reactivity of this dithiane illustrates the concept of umpolung
.
The unpleasant odour of 1,3-propanedithiol has encouraged the development of alternative reagents that generate similar derivatives.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with the formula HSCH2CH2CH2SH. This dithiol
Thiol
In organic chemistry, a thiol is an organosulfur compound that contains a carbon-bonded sulfhydryl group...
is a useful reagent
Reagent
A reagent is a "substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs." Although the terms reactant and reagent are often used interchangeably, a reactant is less specifically a "substance that is consumed in the course of...
in organic synthesis
Organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...
. This liquid, which is readily available commercially, has an intense stench.
Use in organic synthesis
1,3-Propanedithiol is mainly used for the protectionProtecting group
A protecting group or protective group is introduced into a molecule by chemical modification of a functional group in order to obtain chemoselectivity in a subsequent chemical reaction...
of aldehyde
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....
s and ketone
Ketone
In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...
s via their reversible formation of dithiane
Dithiane
A dithiane is a heterocyclic compound composed of a cyclohexane core structure wherein two methylene units are replaced by sulfur centres. The three isomeric parent heterocycles are 1,2-dithiane, 1,3-dithiane and 1,4-dithiane....
s. A prototypical reaction
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
is its formation of 1,3-dithiane from formaldehyde
Formaldehyde
Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...
. The reactivity of this dithiane illustrates the concept of umpolung
Umpolung
Umpolung or polarity inversion in organic chemistry 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 otherwise not be possible. The concept was introduced by...
.
The unpleasant odour of 1,3-propanedithiol has encouraged the development of alternative reagents that generate similar derivatives.
Use in inorganic synthesis
1,3-Propanedithiol reacts with metal ions to form chelate rings. Illustrative is the synthesis of the diiron derivative:- Fe3(CO)12Triiron dodecacarbonylTriiron dodecarbonyl is the chemical compound with the formula Fe312. It was one of the first metal carbonyl clusters synthesized. It is a more reactive source of iron than is iron pentacarbonyl.-General properties:...
+ C3H6(SH)2 → Fe2(S2C3H6)(CO)6 + H2 + Fe(CO)5Iron pentacarbonylIron pentacarbonyl, also known as iron carbonyl, is the compound with formula 5. Under standard conditions Fe5 is a free-flowing, straw-colored liquid with a pungent odour. This compound is a common precursor to diverse iron compounds, including many that are useful in organic synthesis. Fe5 is...
+ CO