An epoxide is a cyclic ether with only three ring atoms. This ring approximately is an equilateral triangle, i.e. its bond angles are about 60°, which makes it highly strained. The strained ring makes epoxides more reactive than other ethers, especially towards nucleophiles. Simple epoxides are named from the parent compound ethylene oxide or oxirane, such as in chloromethyloxirane. As a functional group epoxides obtain the epoxy prefix such as in the compound 1,2-epoxycycloheptane which can also be called cycloheptene epoxide. Ether is the general name for a class of chemical compounds which contain an ether group — an oxygen atom connected to two (substituted) alkyl groups. ... For alternate meanings, such as the musical instrument, see triangle (disambiguation). ... Ring strain is an organic chemistry term that describes the destabilization of a cyclic molecule—such as a cycloalkane—due to the non-favorable high energy spatial orientations of its atoms. ... In chemistry, a nucleophile (literally nucleus lover) is a reagent which is attracted to centres of positive charge. ... The chemical compound ethylene oxide is an important industrial chemical used as an intermediate in the production of ethylene glycol and other chemicals, and as a sterilant for foodstuffs and medical supplies. ... In organic chemistry functional groups are specific groups of atoms within molecules, that are responsible for the characteristic chemical reactions of those molecules. ... In linguistics, a prefix is a type of affix that precedes the morphemes to which it can attach. ...

A polymer made of epoxide units is called a polyepoxide or an epoxy. Epoxy resins are used as adhesives and structural materials. Example: epoxyethane Polymer is a term used to describe molecules consisting of structural units and a large number of repeating units connected by covalent chemical bonds. ... Epoxy or polyepoxide is a thermosetting epoxide polymer that cures (polymerizes and crosslinks) when mixed with a catalyzing agent or hardener. Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A. The first commercial attempts to prepare resins from epichlorohydrin occurred in 1927 in the United... An adhesive is a compound that adheres or bonds two items together. ... Epoxyethane is similar to ethene, with the exception that it does not have a double bond. ...

Synthesis

Epoxides are usually created by one of the following reactions:

• Olefin Peroxidation involves the oxidation of an olefin with a peroxide, usually a peroxyacid like m-CPBA, and proceeds via what is commonly known as the Butterfly Mechanism ^[1]. It is easiest to consider the oxygen to be an electrophile, and the alkene a nucleophile, although they both operate in that capacity, and the reaction is considered to be concerted (the numbers in the mechanism below are for simplification).

• enantioselective alkene epoxidations can be found in the Sharpless epoxidation, the Jacobsen epoxidation and the Shi epoxidation.
• Intramolecular SN2 substitution. This method is a variant of the Williamson ether synthesis. In this case, the alkoxide ion and the halide are right next to each other in the same molecule (such compounds are generically called halohydrins), which makes this a simple ring closure reaction.
• In the Johnson-Corey-Chaykovsky reaction epoxides are generated from carbonyl groups and sulfonium ylides.

A synonym for the more widely accepted term, alkene. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... A peroxy acid is an acid in which an acidic -OH group has been replaced by an -OOH group. ... Chemical structure of meta-chloroperoxybenzoic acid meta-Chloroperoxybenzoic acid (mCPBA) is a peroxy acid with chemical formula C7H5ClO3 and CAS number 937-14-4. ... In chemistry, an electrophile (literally electron-lover) is a reagent attracted to electrons that participates in a chemical reaction by accepting an electron pair in order to bond to a nucleophile. ... In chemistry, a nucleophile (literally nucleus lover) is a reagent which is attracted to centres of positive charge. ... Image File history File links Butterfly Mechanism to synthesize epoxides. ... In chemistry two stereoisomers are said to be enantiomers if one can be superimposed on the mirror image of the other. ... Sharpless epoxidation is a chemical reaction of an allylic alcohol with t-butylperoxide and titanium tetraisopropylate to form an epoxide. ... Jacobsen Rules!!! The Jacobsen Epoxidation is an organic reaction which allows enantioselective synthesis of epoxides from isolated alkenes. ... The Shi epoxidation is a chemical reaction described as an asymmetric epoxidation of olefins with oxone and a fructose-derived catalyst (1). ... Williamson ether synthesis was developed by Alexander Williamson in 1850. ... An alkoxide has an organic group bonded to a negatively charged oxygen atom, they are generally basic. ... A halide is a binary compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative than the halogen, to make a fluoride, chloride, bromide, iodide, or astatide compound. ... A halohydrin is a type of chemical compound or functional group in which one carbon atom has a substituent of the halogen group in a carbon - carbon saturated covalent bond and the other carbon atom has a hydroxyl substituent. ... The Johnson-Corey-Chaykovsky reaction is a chemical reaction in which a carbonyl is converted to an epoxide by the action of a sulfonium ylide. ... Carbonyl group In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom. ... An ylide is a neutral molecule with positive and negative charges on adjacent atoms. ...

Reactions

Typical epoxide reactions are listed below.

• Nucleophilic addition to an epoxide can be base or acid catalyzed.

• Hydrolysis of an epoxide in presence of an acid catalyst generates a glycol. The hydrolysis process of epoxides can be considered to be the nucleophilic addition of water to the epoxide under acidic conditions.
• Reduction of an epoxide with lithium aluminium hydride and water generates an alcohol. This reduction process can be considered to be the nucleophilic addition of hydride (H-) to the epoxide under basic conditions.

• Reduction with tungsten hexachloride and n-butyllithium generates the alkene. This reaction in effect is a de-epoxidation ^[2]:

In organic chemistry, a nucleophilic addition reaction is an addition reaction where in a chemical compound a pi bond is removed by the creation of two new covalent bonds by the addition of a nucleophile. ... Image File history File links Epoxide Opening Mechanism File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Hydrolysis is a chemical reaction or process in which a molecule is split into two parts by reacting with a molecule of water, which has the chemical formula H2O. One of the parts gets an OH- from the water molecule and the other part gets an H+ from the water. ... In organic chemistry, an acid catalyst is a compound such as sulfuric acid(H2SO4) that is used to donate protons. ... Ethylene glycol (IUPAC name:ethane-1,2-diol) is a chemical compound widely used as an automotive antifreeze (coolant). ... Hydrolysis is a chemical reaction or process in which a molecule is split into two parts by reacting with a molecule of water, which has the chemical formula H2O. One of the parts gets an OH- from the water molecule and the other part gets an H+ from the water. ... In organic chemistry, a nucleophilic addition reaction is an addition reaction where in a chemical compound a pi bond is removed by the creation of two new covalent bonds by the addition of a nucleophile. ... In acid catalysis and base catalysis a chemical reaction is catalized by an acid or a base. ... Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. ... Lithium aluminium hydride (LiAlH4), commonly abbreviated to LAH, is a powerful reducing agent used in organic chemistry. ... Impact of a drop of water. ... In chemistry, an alcohol is any organic compound in which a hydroxyl group (-OH) is bound to a carbon atom of an alkyl or substituted alkyl group. ... Tungsten hextachloride is the chemical compound with the formula WCl6. ... An organolithium reagent is a carbon nucleophile similar to a Grignard reagent. ... An alkene in organic chemistry is an unsaturated hydrocarbon containing at least one carbon to carbon double bond. ... Image File history File links Download high-resolution version (925x319, 5 KB) Summary De-epoxidation by tungsten hexachloride Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ...

See also

• polyethers

Ether is the general name for a class of chemical compounds which contain an ether group — an oxygen atom connected to two (substituted) alkyl groups. ...

References

1. ^ Bartlett Rec. Chem. Prog 1950, 11 47.
2. ^ Lower valent tungsten halides. New class of reagents for deoxygenation of organic molecules K. Barry Sharpless, Martha A. Umbreit, Marjorie T. Nieh, Thomas C. Flood J. Am. Chem. Soc.; 1972; 94(18); 6538-6540. Abstract

Karl Barry Sharpless (born April 28, 1941) is an American chemist renowned for his work on organometallic chemistry. ... The Journal of the American Chemical Society (usually abbreviated as , or JACS), is a peer-reviewed scientific journal, published since 1879 by the American Chemical Society. ...

External links

• Link page to external chemical sources.