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A generic epoxide. In organic chemistry, an epoxide is a cyclic ether, where the ether forms a three-atom ring: two atoms of carbon and one atom of oxygen. This triangular structure has substantial ring strain, making epoxides highly reactive, more so than other ethers. They are produced on a large scale for many applications.
In organic chemistry, 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. Episulfides are less common and ...
In alkanes, optimum overlap of atomic orbitals is achieved at 109.5°. The most common cyclic compounds have five or six carbons in their ring. [6] Adolf von Baeyer received a Nobel Prize in 1905 for the discovery of the Baeyer strain theory, which was an explanation of the relative stabilities of cyclic molecules in 1885.
Other processes may take place competitively under basic conditions, particularly when β-elimination is slow or not possible. [6] These pathways likely begin with lithiation of a carbon in the epoxide ring, followed by α-elimination to afford a carbene intermediate. 1,2-hydrogen migration leads to ketones, [2] while intramolecular C–H insertion affords cyclic alcohols with the formation of ...
The mechanism of homogeneous ring-opening metathesis polymerization is well-studied. It is similar to any olefin metathesis reaction. Initiation occurs by forming an open coordination site on the catalyst. Propagation happens via a metallacycle intermediate formed after a 2+2 cycloaddition. When using a G3 catalyst, 2+2 cycloaddition is the ...
In situ nucleophilic opening of equilibrating epoxides is an example of Curtin-Hammett conditions—because the epoxides are equilibrating rapidly relative to the rate of epoxide opening, it is the kinetic barriers of ring opening that control the observed product ratio. In the example below, the product of opening of the terminal epoxide is ...
By Jonathan Stempel (Reuters) -EBay agreed to pay $59 million and upgrade compliance measures to resolve U.S. Department of Justice allegations it didn't try hard enough to stop criminals from ...
Since epoxide is a three-membered ring molecule, it has a high degree of ring strain. Although the carbons in the ring system are tetrahedral, preferring 109.5 degrees between each atom, epoxide strains the ring angles into 60 degrees. To counter this effect, the nucleophilic aza enolates easily react with epoxides to reduce their ring strains.