Formation

Ethers are formed by a type of intermolecular dehydration in which two alcohol molecules are joined together. An example of this is shown here (and in Example 20 of your workbook).

Equation for formation of ether. [64rxn15.JPG]

In this example there are two alcohol molecules which are shown without specifying what alcohols they are by using R to represent alkyl groups. The prime mark on the R in the second alcohol just indicates that it is not necessarily the same group as is in the first alcohol.

Note that acid and heat are used in this reaction. These are the same conditions that were necessary for the intermolecular dehydration used to make esters.

They are also the same conditions that were used in the intramolecular dehydration of alcohols to form alkenes a few lessons ago. So this reaction will be competing with the formation of alkenes from the dehydration of individual alcohol molecules.

Equation for formation of ether showing side reactions. [64rxn16.JPG]

Whether you get an ether, an alkene, or a mixture of both along with the original alcohol or alcohols will depend on such things as the concentration of water, concentration of acid, and the temperature.

These types of factors are very important when you get into synthesizing something from an alcohol. Usually, you get mixtures of various products from any organic reaction. This is true even though we can write an equation, that shows only one product.

Top of Page

E-mail instructor: Sue Eggling

Clackamas Community College
Š2001, 2003 Clackamas Community College, Hal Bender