Fundamentals of Organic ChemistryChemistryAlcohols Phenols and Ethers
Consider the following reactions of tert -butyl methyl ether: Products ( P ₂) anhy. HI ( CH ₃)₃ C - O - CH ₃ conc. HI Products ( P ₁) The products P ₁ and P ₂ , respectively, are:
Options
- A( CH ₃)₃ COH + CH ₃ I and ( CH ₃)₃ CI + CH ₃ OH
- B( CH ₃)₃ CI + CH ₃ OH and ( CH ₃)₃ COH + CH ₃ I
- C( CH ₃)₃ CI + CH ₃ OH in both cases
- D( CH ₃)₃ COH + CH ₃ I in both cases
Correct answer
B. ( CH ₃)₃ CI + CH ₃ OH and ( CH ₃)₃ COH + CH ₃ I
Step-by-step solution
The cleavage of ethers by HI involves the initial protonation of the oxygen atom to form an oxonium ion. For the reaction with concentrated HI : Concentrated HI is an aqueous solution, providing a highly polar medium that stabilizes carbocation intermediates. Thus, the reaction proceeds via an S_N1 mechanism. The C - O bond cleaves to form the highly stable tert-butyl carbocation, which is then attacked by the iodide ion. The products are tert-butyl iodide and methanol. P ₁ : ( CH ₃)₃ CI + CH ₃ OH For the reaction