`(CH_(3))_(3)C-OCH_(3)` on reaction with HI gives `(CH_(3))_(3)C-I and CH_(3)-OH` as the main products and not `(CH_(3))_(3)C-OH and CH_(3)-I`. Explain.

Explanation

The reaction :
`CH_(3)- underset(CH_(3)) underset(|)overset(CH_(3)) overset(|)C-OCH_(3)+HI overset(573K) to CH_(3)- underset(CH_(3)) underset(|)overset(CH_(3)) overset(|)(C)-I+CH_(3)OH`
gives `(CH_(3))_(3)C-I and CH_(3) OH` as the main products and not `(CH_(3))_(3) COH and CH_(3)I`. This is because the reaction occurs by `S_(N)1` mechanism and the formation of products is governed by the stability of carbocation formed from the cleavage of C-O bond in the protonated ether. Since tert butyl carbocation, `(CH_(3))_(3)C^(+)` is more stable than methyl carbocation, `CH_(3)^(+)` therefore, the cleavage of C-O gives more stablecerbocation, `[(CH_(3)),C]^(+)` and methanol. Then iodide ion, `I^(-)` attacks this tert. butylcarbonation to form tert-butyl iodide.