Wurtz reaction.

Explanation

This reaction involves the interaction of two molecules of an alkyl halide (preferably bromide or iodide) in presence of dry ether to form symmetrical alkanes having double the number of carbon atoms present in the alkyl halide. For example,
`underset("Methyl iodide")(CH_(3)I)+2Na+ICH_(3)overset("Ether")(to)2NaI+underset("Ethane")(CH_(3)CH_(3))`
`underset("Ethyl bromide")(C_(2)H_(5)Br)+2Na+BrC_(2)H_(5)overset("Ether")(to)2NaBr+underset("Butane")(C_(4)H_(10))`
When a mixture of two different alkyl halides is used a mixture of alkanes is formed.
For example, on heating methyl iodide and ethyle iodine with sodium, mixture of ethane, propane and butane is obtained as illustrated below :
`CH_(3)I+2Na+IC_(2)H_(5)toCH_(3)C_(2)H_(5)+2NaI`
`CH_(3)I+2Na+ICH_(3)toCH_(3)CH_(3)+2NaI`
`C_(2)H_(5)I+2Na+IC_(2)H_(5)toC_(2)H_(5)C_(2)H_(5)+2NaI`
Since the mixture of alkanes is difficult to separate, this method is suitable only for symmetrical alkanes, i.e., alkanes having even number of carbons. However, the method is not suitable for the preparation of unsymmetrical alkanes. Recently, Corey and House have suggested a method for the preparation of unsymmetrical alkanes. This method is called Corey - House reaction.