Why is Wurtz reaction not preferred for the preparation of alkanes containing odd number of carbon atoms? Illustrate your answer by taking one example.

Explanation

For preparing alkanes containing odd number of carbon atoms, a mixture of two alkyl halides has to be used. These two alkyl halides may react in three different ways producing a mixture of three alkanes instead of desired alkane. For example, Wurtz reaction between bromoethane and l-bromopropane give the following three alkanes instead of a single alkane of odd number of C-atoms.