Among the following ethers, which one will produce methyl alcohol on treatment with hot concentrated HI?
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Answer
(1) [figure]
Solution
With HI, the ether is first protonated.
For methyl ethers of primary/secondary alkyl groups, I- attacks the less hindered CH3 group (SN2) ⇒ CH3I + alkanol; no methyl alcohol is formed.
For tert-butyl methyl ether, the C–O bond to the tertiary carbon breaks (SN1, stable tertiary carbocation).
As per NCERT:
(CH3)3C-O-CH3 + HI CH3-OH + (CH3)3C-I
∴ Only option (1) gives methyl alcohol.
Answer: (1)