NEET2017ChemistryAlcohols Phenols and EthersActual
( CH ₃ )₃ COCH ₃ and CH ₃ OC ₂ H ₅ are treated with hydroiodic acid. The fragments obtained after reactions are respectively
Options
- A( CH ₃ )₃ CI + CH ₃ OH ; CH ₃ I + C ₂ H ₅ OH
- B( CH ₃ )₃ CI + CH ₃ OH ; CH ₃ OH + C ₂ H ₅ I
- C( CH ₃ )₃ COH + CH ₃ I ; CH ₃ OH + C ₂ H ₅ I
- DCH ₃ I + ( CH ₃ )₃ COH ; CH ₃ I + C ₂ H ₅ OH
Correct answer
A. ( CH ₃ )₃ CI + CH ₃ OH ; CH ₃ I + C ₂ H ₅ OH
Step-by-step solution
When mixed ethersare used, the formation of alkyl iodide depends on the nature of alkyl groups. Methyl iodide is formed when one group is methyl and the other a primary or secondary alkyl group. Here reaction follows S _ N 2 mechanism and because of the steric effect of the larger group, I ⁻ attacks the smaller (Me) group. CH ₃ OC ₂ H ₅+ HI CH ₃ I + C ₂ H ₅ OH When the substrate is a methyl t -alkyl ether, the products are t-R I and MeOH . Here reaction follows S _ N 1 mechanism and formation of products is control