Aldehydes & Ketones

Question 1

By considering the mechanism of nucleophilic addition of a ketone, explain why the product has no effect on plane polarised light

Answer 1

The plane carbonyl group undergoes a nucleophilic attack from H- and this happens from either side of the group. This produces an alcohol which exists in 2 chiral forms. This is a racemic mixture and each enantiomer rotates the plane of polarised light equally so their effect cancel each other