Benzoin Condensation

Reaction :-

The benzoin condensation involves the treatment of an aromatic aldehyde with aqueous alcoholic KCN or NaCN. The products are alpha hydroxy ketones. for example, Benzaldehyde reacts with alcoholic KCN to form benzoin, notice that two molecules of benzaldehyde take part in the reaction.

Mechanism :-

The above reaction takes place as following.........

The cyanide ion reacts readily with benzaldehyde and enables the formation of carbanion (A)

The carbanion (A) can then reacts with another benzaldehyde molecule. subsequent proton transfer and loss of the cyanide ion gives benzoin.

Puvvukonvict.....................