Chemistry - Aromatic Hydrocarbon Question with Solution | TestHub
The Lewis acid usually reacts with the acyl halide to form an acylium ion. The acylium ion is stabilized by resonance. The acylium ion acts as an electrophile attacking the benzene ring to form an arenium ion. The arenium ion then loses a proton to generate the final product. Powerful electron withdrawing groups on the benzene ring such as another acyl group will retard this reaction. Naphthalene is the simplest and most important of the fused ring hydrocarbons. Five percent of all constituents of coal tar are naphthalene. Naphthalene can be manufactured using the Friedel-Crafts reaction via the reaction pathway shown below:
Which of the following is an acylium ion?
Options:
Answer:
Solution:
Solution:
The acylium ion is a resonance-stabilized carbocation with a positive charge on the carbonyl carbon, as shown in option B.
Concepts:
Friedel-Crafts acylation, Lewis acid-base reaction, acylium ion, resonance stabilization, electrophilic aromatic substitution.