They are alkoxy derivatives of alkanes in which a hydrogen atom of alkane (R – H) is replaced by alkoxy group ( – O – R) and divalent oxygen atom is attached to two alkyl groups or two aryl groups or one alkyl and one aryl group.
Ethers are organic oxides R – O – Ar, Ar – O – Ar.
E.g. R – O – R or C2H5 – O – C2H5.
Ethers are classified into two groups as follows :
(1) Simple or symmetrical ether :
The ethers in which both alkyl (or aryl) groups attached to the oxygen atom are same are called simple ethers.
E.g. (R – O – R), CH3 – O – CH3, dimethyl ether; C6H5 – O - C6H5 diphenyl ether.
(2) Mixed or unsymmetrical ethers :
The ethers in which the two alkyl (or aryl) groups attached to the oxygen atom are different are called mixed ethers.
E.g. (R – O – R), CH3 – O – C2H5 ethyl methyl ether; C2H5 – O – C6H5 ethyl phenyl ether.
