4 Chemical
Reactions
Reactions
Reactions
Reactions
Reactions
Rationalised 2023-24
237
Aldehydes, Ketones and Carboxylic Acids
(iii) Some important examples of nucleophilic addition and
nucleophilic addition-elimination reactions:
(a) Addition of hydrogen cyanide (HCN): Aldehydes
and ketones react with hydrogen cyanide (HCN)
to yield cyanohydrins This reaction occurs very
slowly with pure HCN Therefore, it is catalysed
by a base and  the generated cyanide ion (CN
being a stronger nucleophile readily adds to-)
carbonyl compounds to yield corresponding
cyanohydrin Cyanohydrins 
are 
useful 
synthetic
intermediates