Write the mechanism of the reaction of HI with methoxymethane.

Explanation

Ethermolecule gets protonated.

Step 2 The protonated ether undergoes `S_(N)2` attack by `I^(-)` lion

IF HI is in exces, the methanol formed in step 2 is also converted into methyl iodide as:
`CH_(3)-O-H+H-Ioverset("Protonation")to underset("PRotonated methyl alcohol") overset(H) overset(|+)(CH_(2)-O-H+)I^(-)`
`I^(-)+CH_(3)-overset(H)overset(|+)O-H underset("Slow")overset(S_(N^(2)))to underset("Methyl iodid") (CH_(3)I)+ underset("Water")(H_(2)O)`