cyanhydrin

A cyanhydrin is a molecule that contains both a nitrile group (CN) and a hydroxyl group (OH) attached to the same carbon atom. This specific arrangement of functional groups gives cyanhydrins unique chemical properties. They are often formed by the addition reaction of hydrogen cyanide (HCN) to an aldehyde or a ketone. This reaction, known as the cyanhydrin formation reaction, is an equilibrium process.

The general formula for a cyanhydrin derived from an aldehyde is RCH(OH)CN, and from a ketone is R1R2C(OH)CN. The carbon atom bearing the hydroxyl and nitrile groups is chiral, meaning that if the R groups are different (as in the case of ketones with two different R groups, or aldehydes where R is not H), the cyanhydrin can exist as a pair of enantiomers.

Cyanhydrins are important intermediates in organic synthesis. They can be hydrolyzed to alpha-hydroxy acids, reduced to beta-amino alcohols, or reacted with other reagents to form a variety of valuable compounds. For example, the cyanhydrin of acetone, acetone cyanohydrin, is a precursor to methyl methacrylate, a monomer used in the production of acrylic plastics. However, due to the toxicity of hydrogen cyanide, their preparation and handling require careful safety precautions.