Question

Explain the mechanism of the reaction of diethyl ether with HI.

Hint:

In ether cleavage reactions, the bond between the oxygen and carbon atoms is broken, with the nucleophile attacking the less sterically hindered carbon.

Answer 1

Step 1: Reaction Mechanism Overview
The reaction of diethyl ether with HI involves the cleavage of the ether bond, resulting in the formation of ethyl iodide and ethanol. The reaction proceeds via a nucleophilic substitution mechanism (S\(_N\)2).
Step 2: Mechanism
1. The protonation of the ether oxygen occurs due to the acidic nature of HI: \[ \text{CH}_3\text{CH}_2\text{OCH}_2\text{CH}_3 + \text{HI} \rightarrow \text{CH}_3\text{CH}_2\text{OCH}_2\text{CH}_3^+ + \text{I}^- \] 2. The protonated ether is now more electrophilic and undergoes cleavage, with the iodide ion (\(I^-\)) attacking one of the ethyl groups, leading to the formation of ethyl iodide: \[ \text{CH}_3\text{CH}_2\text{OCH}_2\text{CH}_3^+ \rightarrow \text{CH}_3\text{CH}_2\text{I} + \text{CH}_3\text{CH}_2\text{OH} \] Final Answer: The reaction of diethyl ether with HI produces ethyl iodide and ethanol via an S\(_N\)2 mechanism. Correct Answer: Ethyl iodide and ethanol are formed.