Ether

: This article is about ether as a general class of chemical compounds. For other meanings, see Ether (disambiguation)

Chemical reactions

Synthesis

• R-OH + R-OH → R-O-R + H₂O
• : This direct reaction requires drastic conditions (heat and an acid catalyst) and is usually not applicable. Such conditions can destroy the delicate structures of some functional groups. There exist several milder methods to produce ethers.
• R-O^- + R-X → R-O-R + X^-
• : This is called Williamson ether synthesis. It involves treatment of a parent alcohol with a strong base to form the alkoxide anion followed by addition of an appropriate aliphatic compound bearing a suitable leaving group (R-X). Suitable leaving groups (X) include iodide, bromide, or sulfonates. This method does not work if R is aromatic like in bromobenzene. Likewise, this method only gives the best yields for primary carbons, as secondary carbons will undergo E2 elimination on exposure to the basic alkoxide anion used in the reaction. Aryl ethers can be prepared in the Ullmann condensation.
• R₂C=CR₂ + R-OH → R₂CH-C(-O-R)-R₂ (under acid catalysis)

Reactions

Ethers are of very low chemical reactivity. They are hydrolyzed only under drastic conditions like heating with boron tribromide or boiling in hydrobromic acid. Lower mineral acids containing a halogen, such as hydrochloric acid will cleave ethers, but very slowly. Hydrobromic acid and hydroiodic acid are the only two that do so at an appreciable rate.

Related Topics:
Reactivity - Hydrolyzed - Boron tribromide - Hydrobromic acid - Hydrochloric acid - Hydroiodic acid

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Ethers can act as Lewis bases. For instance, diethyl ether forms a complex with boron compounds, such as boron trifluoride diethyl etherate F3B:O(CH2CH3)2.

Related Topics:
Lewis base - Boron - Boron trifluoride

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Epoxides, or cyclic ethers in three-membered rings, are highly susceptible to nucleophilic attack and are reactive in this fashion.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Primary and secondary ethers with a CH group next to the ether oxygen easily form highly explosive organic peroxides (e.g. diethyl ether peroxide) in the presence of oxygen, light, and metal and aldehyde impurities. For this reason ethers like diethyl ether and THF are usually avoided as solvents in industrial processes.

Related Topics:
Explosive - Organic peroxide - Diethyl ether peroxide - Aldehyde - THF - Solvent

~ ~ ~ ~ ~ ~ ~ ~ ~ ~