Question

What is the reaction of hot and cold $HI$ on isopropyl methyl ether?

Answer 1

The concept of reaction of hydrogen halides with ethers that cleaves the carbon oxygen bond of ethers and this cleavage takes place in the drastic conditions where cold condition yields alcohol and hot condition yields iodide compounds. This fact gives you the correct answer.

Complete step by step answer:

In our classes of organic chemistry, we have studied about the various types of reaction taking place by the addition of any compound with acids and bases which includes the substitution reaction, that is, which can be unimolecular or bimolecular substitution.

We shall now see what happens when isopropyl methyl ether is treated with hot as well as cold hydrogen iodide.

- Isopropyl methyl ether when treated with cold hydrogen iodide the product formed will be isopropyl alcohol and methyl; iodide. The type of reaction that takes place is the ${{S}_{N}}2$ reaction. The reaction is as shown below,

- When this ether is treated with hot hydrogen iodide then the is removal of water molecule from the reactant and product will be isopropyl iodide and methyl iodide and the reaction is as shown,

This reaction proceeds as one molecule of $HI$ reacts with isopropyl alcohol to give isopropyl iodide with release of the water molecule.

Note: Isopropyl methyl ether is also called 2 – methoxy propane or just methoxypropane which is having methyl and isopropyl as two alkyl groups attached to a single oxygen atom. This compound was once used as anaesthetic and is a clear colourless flammable liquid. This compound was used as an alternative to diethyl ether for its greater potency.