JEE MainChemistryAlcohols Phenols and Ethers
When 1-(2-methoxypropan-2-yl)-1-methylcyclobutane is treated with excess heated HI , the major organic product formed is:
Options
- A1-iodo-1,2,2-trimethylcyclopentane
- B1-(2-iodopropan-2-yl)-1-methylcyclobutane
- C1-(tert-butyl)-1-iodocyclobutane
- D1,5,5-trimethylcyclopent-1-ene
Correct answer
A. 1-iodo-1,2,2-trimethylcyclopentane
Step-by-step solution
Step 1: In the presence of excess heated HI , the ether undergoes cleavage via an S _ N 1 mechanism because it contains a tertiary alkyl group. The oxygen is protonated, and the C-O bond breaks to form a stable tertiary carbocation, the 2-(1-methylcyclobutyl)propan-2-yl cation, along with methanol (which further reacts with HI to form methyl iodide). Step 2: The formed carbocation is adjacent to a highly strained four-membered cyclobutane ring. To relieve ring strain, a C-C bond of the cyclobutane ring migrates to