Question

In the given reaction the product P is:

A)

B)

C)

D)

Answer 1

Hint: The cyclohexane reacts with hydrogen fluoride to form a cation. Benzene gives a substitution reaction with this cation. The product has two joined rings.

Complete step by step answer:
To attach substituents on aromatic rings the Friedel craft alkylation reactions are used. Friedel craft alkylation reactions are the reaction of aromatic rings with alkyl groups in presence of Lewis acid.
Firstly, the cyclohexene reacts with acid hydrogen fluoride, so cyclohexene abstract protons from the hydrogen fluoride form a cation of cyclohexane.
The reaction is shown as follows:

The benzene attacks on the cyclohexyl cation to form the cation again. The attack of benzene attacks on the cyclohexane joins the two rings or we can say alkylate the benzene ring.
The reaction is shown as follows:

The positive charge is stabilized by the delocalization in the benzene ring. The abstraction of hydrogen from the benzene ring gives the final product.
The product is shown as follows:

So, the product P of the reaction of benzene with cyclohexene in presence of Lewis acid hydrogen fluoride is 1-cyclohexylbenzene.

Therefore, option (A) is correct.

Note: The given reaction of cyclohexane and benzene in presence of hydrogen fluoride is an example of Friedel craft alkylation. Which is an electrophilic aromatic substitution type reaction. The alkyl groups are electron donating groups, so increases the nucleophilicity of the species. So, the product of Friedel craft alkylation is more nucleophilic than the reactant.