Eschenmoser sulfide contraction
Encyclopedia
The Eschenmoser sulfide contraction is an organic reaction
first described by Albert Eschenmoser
for the synthesis of 1,3-dicarbonyl compounds from a thioester
. The method requires a base and a tertiary phosphine. The method is of some relevance to organic chemistry
and has been notably applied in the vitamin B12 total synthesis
.
A base abstracts the labile hydrogen atom in the thioester, a sulfide anion is formed through an episulfide
intermediate which is removed by the phosphine.
efforts, like that of fuligocandin A and B , cocaine
,diplodialide A and isoretronecanol
An example of general synthetic utility is the synthesis of novel carbapenem
s
Organic reaction
Organic reactions are chemical reactions involving organic compounds. The basic organic chemistry reaction types are addition reactions, elimination reactions, substitution reactions, pericyclic reactions, rearrangement reactions, photochemical reactions and redox reactions. In organic synthesis,...
first described by Albert Eschenmoser
Albert Eschenmoser
Albert Eschenmoser is a Swiss chemist working at the ETH Zurich and The Scripps Research Institute.His work together with Lavoslav Ružička on terpenes and the postulation of squalene cyclization to form lanosterol improved the insight into steroid biosynthesis.In the early 1960s, Eschenmoser began...
for the synthesis of 1,3-dicarbonyl compounds from a thioester
Thioester
Thioesters are compounds with the functional group C-S-CO-C. They are the product of esterification between a carboxylic acid and a thiol. Thioesters are widespread in biochemistry, the best-known derivative being acetyl-CoA.-Synthesis:...
. The method requires a base and a tertiary phosphine. The method is of some relevance to organic chemistry
Organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation of carbon-based compounds, hydrocarbons, and their derivatives...
and has been notably applied in the vitamin B12 total synthesis
Vitamin B12 total synthesis
Vitamin B12 total synthesis in chemistry describes the total synthesis of the complex biomolecule vitamin B12. A method first reported by the groups of Robert Burns Woodward and Albert Eschenmoser in 1973 is considered a classic in this research field....
.
A base abstracts the labile hydrogen atom in the thioester, a sulfide anion is formed through an episulfide
Episulfide
Episulfides are a class of organic compounds that contain a saturated heterocyclic ring consisting of two carbon atoms and one sulfur atom. It is the sulfur analogue of an epoxide or aziridine. They are also known as thiiranes, olefin sulfides, thioalkylene oxides, and thiacyclopropanes.The parent...
intermediate which is removed by the phosphine.
Scope
The Eschenmoser sulfide contraction method has been employed in a number of total synthesisTotal synthesis
In organic chemistry, a total synthesis is, in principle, the complete chemical synthesis of complex organic molecules from simpler pieces, usually without the aid of biological processes. In practice, these simpler pieces are commercially available in bulk and semi-bulk quantities, and are often...
efforts, like that of fuligocandin A and B , cocaine
Cocaine
Cocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
,diplodialide A and isoretronecanol
An example of general synthetic utility is the synthesis of novel carbapenem
Carbapenem
Carbapenems are a class of β-lactam antibiotics with a broad spectrum of antibacterial activity. They have a structure that renders them highly resistant to most β-lactamases...
s