Question

Which of the following alkyl halides is not suitable for Corey-House synthesis of alkanes?
A.$C{H_3}Br$
B.${C_2}{H_5}I$
C.$C{H_3}C{H_2}C{H_2}I$
D.${(C{H_3})_3}CBr$

Answer 1

Hint:In the given question firstly we have to define what the Corey-House synthesis means and what is the working of the process. Along with that the reaction of synthesis ${R_2}CuLi + {R^|}X \to R - {R^|} + R - Cu + LiX$ should also be mentioned. Now this is used to get the alkane but the tertiary carbon does not follow it and is eliminated in order to form an alkene.

Complete step by step answer:
In the given question we have to first find out the working of the Corey-House synthesis and what exactly they are used to get as the desired product.

Now firstly the Corey-House synthesis is a process of converting the alkyl halides into the alkanes for any given set of the reactive halides.
Now the process that exactly goes is that :

The alkyl halide ${R^|}X$ is reacted with the ${R_2}CuLi$ where both the alkyl groups can vary or not that depends.
Now this will react in order to form an alkane, one cuprite in the alkyl group and one salt.

So the given reaction for the given process would be :
${R_2}CuLi + {R^|}X \to R - {R^|} + R - Cu + LiX$

But in the case of tertiary halide the reaction doesn't continue like that as they will thus perform the reaction of elimination therefore yielding the alkenes.

This happens due the formation of the double bond between the carbons as the hydrogen gas is liberated.

Hence the correct option is option D, ${(C{H_3})_3}CBr$ .


Note:Corey-House Reaction is also called 'coupling of alkyl halides with organometallic compounds'. It is a better method than Wurtz reaction. An alkyl halide and a lithium dialkyl copper are reacted to give a higher hydrocarbon.