Question

. Write a mechanism for the cleavage of butyl isopropyl ether with HI at 100°C to form exclusively isopropyl alcohol and 1-iodobutane. Explain why butyl alcohol and isopropyl iodide are not formed in the reaction.

Answer 1

Step-by-step explanation:

In this reaction, the ether is cleaved by SN2 , as I⁻ is a strong nucleophile

So we have the following steps

• SN2

1. Protonation of oxygen in ether, improving the ability of both sides to be a leaving group as alchohols
2. I⁻ performs nucleophilic attack on 1st carbon of butyl side, releasing Isopropanol as leaving group and leaving Iodobutane behind

Now, even though butanol can become a leaving group in this reaction, this is unfavourable, as isopropyl group has large steric hindrance which prevents nucleophilic attack on isopropyl side of the ether.