Question

What are X, Y, Z in the following reactions?

• A. figA
• B. figB
• C. figC
• D. figD

Hint:

Aryl alkyl ethers undergo cleavage at alkyl–O bond with HX due to resonance stabilization of aryl oxygen bond.

Answer 1

The Correct Option is B

Concept: Ether cleavage with hydrogen halides depends on the nature of alkyl or aryl–alkyl ethers. Aryl–alkyl ethers undergo cleavage at alkyl–oxygen bond because aryl–O bond has partial double bond character.

Step 1: Reaction with HBr. Phenetole is: \[ C_6H_5-O-CH_2CH_3 \] On heating with HBr, cleavage occurs at alkyl side: \[ C_6H_5OH + C_2H_5Br \] Thus: \[ X = Phenol,\quad Y = Ethyl bromide \]

Step 2: Bromination reaction. Bromine in acetic acid causes electrophilic substitution on activated aromatic ring. Ethoxy group is o,p-directing. Major product is para substituted compound: \[ p\text{-bromophenetole} \] Thus: \[ Z = p\text{-bromophenetole} \]

Step 3: Final answer. \[ X=Phenol,\quad Y=Ethyl bromide,\quad Z=p\text{-bromophenetole} \] Hence option: \[ \boxed{B} \]