Two molecules of an alcohol can be condensed, with the removal of water, to form an ether:




Ethers are named according to the radicals on either side of the central oxygen. CH-O-CH is methyl ethyl ether and anisole is methyl phenyl ether.

Ethers are chemically unreactive, yet are good solvents for hydrocarbons, which makes them useful as inert media for organic reactions.

Ethers and water generally show opposite trends in dissolving other molecules. Because ethers and water are immiscible, they are useful in two-layer separation schemes in organic chemistry.

Ethers are volatile and low-boiling because of the absence of hydrogen bonds in the liquid, and this volatility makes them flammable and dangerous. Diethyl ether, CH-O-CH, is a common anaesthetic, but one with a serious spark hazard.