Consider the following reaction and identify the products A and B: (benzyl phenyl ether)
Answer: (C) (C) A = (benzyl iodide) and B = (phenol). \textbf{Answer:} (C) A = (benzyl iodide) and B = (phenol) \textbf{Solution:} In the HX cleavage of an unsymmetrical alkyl–aryl ether, the iodide ion attacks the alkyl carbon, never the aromatic carbon (the aryl C–O bond has partial double-bond character and is not cleaved).
- A.(A) A = (toluene) and B = (phenol)
- B.(B) A = (benzyl alcohol) and B = (iodobenzene)
- C.(C) A = (benzyl iodide) and B = (phenol)✓
- D.(D) A = (toluene) and B = (iodobenzene)
Correct Answer
(C) (C) A = (benzyl iodide) and B = (phenol)
Solution & Explanation
\textbf{Answer:} (C) A = (benzyl iodide) and B = (phenol) \textbf{Solution:} In the HX cleavage of an unsymmetrical alkyl–aryl ether, the iodide ion attacks the alkyl carbon, never the aromatic carbon (the aryl C–O bond has partial double-bond character and is not cleaved). Here attacks the benzylic carbon of benzyl phenyl ether, breaking the alkyl C–O bond. This gives benzyl iodide (A) and the phenoxy fragment ends up as phenol (B). Iodobenzene is NOT formed.
