Question

Intramolecular reactions are also observed in Friedel–Crafts alkylation. Draw the intramolecular alkylation product formed from each of the following reactants. (Watch out for rearrangements!)

Short answer

The Friedel-craftsalkylation comes under the electrophilic substitution reaction. The alkyl group is substituted in this reaction.

Step-by-step solution

Friedel-crafts alkylation

The Friedel-craftsalkylation comes under the electrophilic substitution reaction. The alkyl group is substituted in this reaction.

Friedel-crafts acylation

The Friedel-crafts acylation reaction also comes under the electrophilic substitution reaction. The acyl group is substituted in this reaction.

Explanation

a. The given compound undergoes Friedel craft alkylation as:

In this conversion, the tertiary carbocation is formed which is substituted on the benzene through intramolecular rearrangement.

b. The given compound undergoes Friedel craft alkylation. In this conversion, the OH is eliminated as the water molecule in the acidic medium. The mechanism proceeds with the formation of the tertiary carbocation which undergoes 1,2 hydrogen shift and forms the final product as:

c. The given compound undergoes Friedel craft alkylation. In this conversion, the chloride ion is eliminated and gives the primary carbocation which further undergoes 1,2-shift carbocation.

After the 1,2-shift, the secondary carbocation is generated and forms the product as: