Question

What type of nucleophilic substitution (\( \text{S}_\text{N}1 \) or \( \text{S}_\text{N}2 \)) occurs in the hydrolysis of 2-Bromobutane to form \( (+-) \)-Butan-2-ol? Give reason.

Hint:

In \( \text{S}_\text{N}1 \) reactions, the rate-determining step is the formation of a carbocation intermediate. This intermediate can be attacked from either side, leading to racemization of the product.

Answer 1

Step 1: The reaction follows an \( \text{S}_\text{N}1 \) mechanism. This is due to the formation of a planar carbocation, which can be attacked by the nucleophile from either side. This leads to racemization of the product. \[ \text{CH}_3\text{CH}_2\text{C(Br)}\text{H}_2 \rightarrow \text{CH}_3\text{C}(\text{+})\text{H}_2 \] The reaction is accompanied by racemization, and the intermediate carbocation is formed in an \( \text{S}_\text{N}1 \) reaction.