Ethers
Ethers are a class of organic compounds that contain an ether group. An ether group is an oxygen group connected to 2 alkyl or aryl groups. They follow the general formula R-O-R'. The C-O-C linkage is characterized by bond angles of 104.5 degrees, with the C-O distances being about 140pm. The oxygen of the ether is more electronegative than the carbon. Thus, the alpha hydrogens are more acidic than in regular hydrocarbon chains (Figure 1).
Naming
There are two ways to name ethers. The most common way is to identify the alkyl groups on either side of the oxygen atom in alphabetical order, then write "ether." For example, ethyl methyl ether is the ether that has an ethyl group and a methyl group on either side of the oxygen atom. If the two alkyl groups are identical, the ether is called di[alkyl] ether. For example, diethyl ether is the ether with an ethyl group on each side of the oxygen atom.
The other way of naming ethers is the formal, IUPAC method. This way, the form is [short alkyl chain][oxy][long alkyl chain]. For example, the IUPAC name for ethyl methyl ether would be methoxyethane.
In cyclic ethers, the stem of the compound is known as a oxacycloalkane. The "oxa" is anindicator of the replacement of the carbon by an oxygen in the ring. An example is oxacyclopentane, a five-membered ring in which there are four carbon (not five, as "pent-" suggests!) atoms and one oxygen in the ring.