Question 1

Which type of reaction is illustrated by the transformation of the given reactant (a benzene ring with a $$-CH_2COCl$$ group) to the product (a bicyclic ketone) using $$1.\ $$AlCl_3$$ and 2$$.\ H_2O$$?

Accepted Answer

Intramolecular Friedel-Crafts acylation (cyclization)

Question 2

What is the role of $$AlCl_3 in $$the reaction shown?

Accepted Answer

It acts as a Lewis acid to generate an acylium ion from the acyl chloride.

Question 3

Which intermediate is formed after the reaction of the acyl chloride with $$AlCl_3$$?

Accepted Answer

An acylium ion $$\left(PhCH_2CO^+\right)$$

Question 4

What is the driving force for the cyclization step in this reaction?

Accepted Answer

Formation of a five-membered ring fused to a benzene ring (indanone system)

Question 5

Which of the following best describes the product of this reaction?

Accepted Answer

A five-membered ring ketone fused to a benzene ring (1-indanone)

Question 6

What is the first step in the mechanism of this reaction?

Accepted Answer

Coordination of $$AlCl_3 to $$the carbonyl oxygen of the acyl chloride

Question 7

Which of the following statements about the mechanism is correct?

Accepted Answer

The aromatic ring acts as a nucleophile attacking the acylium ion.

Question 8

Why is water added in the second step of the reaction?

Accepted Answer

To neutralize the $$AlCl_3$$ and hydrolyze the complexed product

Question 9

Which of the following is a possible side product if the reaction is not controlled properly?

Accepted Answer

Polyacylated aromatic compounds

Question 10

What is the electrophile in the key cyclization step of this reaction?

Accepted Answer

The acylium ion $$\left(RCO^+\right)$$

Question 11

Which of the following best describes the mechanism for the formation of the product?

Accepted Answer

Electrophilic aromatic substitution followed by hydrolysis

Question 12

What is the hybridization of the carbonyl carbon in the final product?

Accepted Answer

$$sp^2$$

Friedel–Crafts Acylation and Intramolecular Cyclization Mechanism

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