Question

Out of ‘X’ and ‘Y’ , which one will form product with inversion of configuration and why?

Hint:

Think of $S_N2$ as an "umbrella flipping inside out" during a storm to remember the concept of inversion.

Answer 1

Step 1: Conceptual Overview:
Inversion of configuration, also known as Walden Inversion, occurs during \( S_N2 \) (bimolecular nucleophilic substitution) reactions, where the configuration of the chiral center is flipped.
Step 2: Detailed Explanation:
The compound 'Y' follows the \( S_N2 \) mechanism, which means the rate of reaction depends on both the concentration of the nucleophile and the substrate. In an \( S_N2 \) reaction, the nucleophile (\( OH^- \)) attacks the carbon atom from the side opposite to the leaving group (\( Br^- \)). This backside attack causes a simultaneous breaking of the bond between the carbon and the leaving group and the formation of a new bond between the carbon and the nucleophile.
As this process occurs, the configuration of the carbon atom undergoes a complete inversion, similar to how an umbrella flips in a strong wind. This results in a product where the configuration of the chiral center is inverted by 100%.
Step 3: Final Conclusion:
The compound 'Y' forms a product with an inversion of configuration due to the backside attack of the nucleophile in the \( S_N2 \) process.