Question

An $S_{N}2$ reaction at an asymmetric carbon of a compound always gives:

• A. A mixture of diastereomers
• B. A single stereoisomer
• C. A product with opposite optical rotation
• D. An enantiomer of the substrate

Answer 1

The correct option is B A single stereoisomer

$S_{N}2$ reaction at asymmetric carbon occurs with inversion of configuration and a single stereoisomer is formed because the reactants and products are not enantiomers. Therefore the sign of optical rotation may or may not change.