Question

Which of the following reaction can be employed for getting unsymmetrical alkanes in good yield?

• A. Wurtz reaction
• B. Corey-House synthesis
• C. Both (a) and (b)
• D. None of the above

Answer 1

The correct option is B Corey-House synthesis

This method is a better method for the preparation of unsymmetrical alkane. In this reaction an alkyl halide and a lithium dialkyl copper are reacted to give a higher hydrocarbon.
$R^{\prime }-X+R_2-CuLi\to R-R^{\prime }+R-Cu+LiX$
(R and R' may be same or different)
Below reactions are example of Corey House synthesis for unsymmetrical and symmetrical alkanes.


In Wurtz reaction, when different alkyl halides are taken it forms traces of undesirable hydrocarbons by disproportionation reaction. In this case, we get hydrocarbon with even number of C atoms and a mixture of products. Hence, it is not a good method to obtain alkanes with odd number of carbons.

Hence, option (b) is correct.