Question

$S_{N}1$ reaction on optically active substrates mainly gives:

• A. retention in configuration
• B. inversion in configuration
• C. racemic product
• D. no product

Answer 1

The correct option is C racemic product

Since the nucleophile attacks the carbocation only after the leaving group has departed, in $S_{N}1$, there is no need for back-side attack. In carbocation, all its substitutents are in the same plane, so that the nucleophile can attack from either side. As a result, both enantiomers are formed in a $S_{N}1$ reaction, leading to a racemic mixture of both enantiomers.

Hence, the correct option is C