Among the follwing ethers, which one will produce methyl alcohol on treatment with hot concentrated `HI`?

Options

A. `CH_(3)-CH_(2)-underset(CH_(3))underset(|)(CH)-O-CH_(3)`
B. `CH_(3)-overset(CH_(3))overset(|)underset(CH_(3))underset(|)(C)-O-CH_(3)`
C. `CH_(3)-underset(CH_(3))underset(|)(CH)-CH_(2)-O-CH_(3)`
D. `CH_(3)-CH_(2)-CH_(2)-CH_(2)-O-CH_(3)`

Answer

B

Explanation

Because only this ether reacts by `S_(N)l` mechanism:
`(CH_(3))_(3)C-O-CH_(3)overset(HI)underset(Delta)(rarr)(CH_(3))_(3)C-I+CH_(3)OH`
Others react by `S_(N)2` mechanism and thus yield from `CH_(3)I`.