How do you synthesise a cyanohydrin?

A cyanohydrin is synthesised by reacting a carbonyl compound with hydrogen cyanide (HCN) in the presence of a base.

Cyanohydrins are organic compounds that contain a hydroxyl group (-OH) and a nitrile group (-CN) attached to the same carbon atom. They are synthesised through the nucleophilic addition reaction of a carbonyl compound (either an aldehyde or a ketone) with hydrogen cyanide (HCN). This reaction is also known as cyanohydrin formation.

The first step in the synthesis of a cyanohydrin involves the deprotonation of hydrogen cyanide by a base to form the cyanide ion (CN-). This cyanide ion is a strong nucleophile, which means it is attracted to the electrophilic carbon atom in the carbonyl compound. The cyanide ion attacks the carbonyl carbon, forming a new carbon-carbon bond and pushing the electrons in the carbonyl double bond onto the oxygen atom. This results in the formation of an intermediate compound, which is then protonated by the base to form the final cyanohydrin product.

The reaction is reversible, and the equilibrium can be shifted towards the product side by using an excess of hydrogen cyanide. The reaction is also exothermic, which means it releases heat. Therefore, it is usually carried out at room temperature to control the reaction rate and prevent side reactions.

The synthesis of cyanohydrins is an important reaction in organic chemistry because cyanohydrins can be easily converted into other useful compounds, such as carboxylic acids, amides, and amines. However, it should be noted that hydrogen cyanide is a highly toxic and dangerous compound, and the reaction should be carried out with caution in a well-ventilated area and with appropriate safety measures.