Cyanohydrin

Cyanohydrins (synonym: α - hydroxynitriles ) contain, bonded to the same carbon atom, a hydroxy group and a nitrile group, that can therefore be referred to as the gem- hydroxynitriles. Are formed in the addition reaction of hydrogen cyanide to the carbonyl group of aldehydes or ketones. The structure formula of the semi- cyanohydrins is R is-CH (OH) -CN (R = alkyl or aryl ), when it was assumed that in the synthesis of an aldehyde. From ketones R2C = O and hydrocyanic acid is obtained, however, the half- cyanohydrins structural formula R2C (OH ) -CN. Using the enzyme ( R) - Oxynitrilase can be obtained enantiomerically pure (R ) - cyanohydrins from aldehydes directly.

The cyanohydrins are starting materials for a number of important organic substances. By acid hydrolysis of α -hydroxycarboxylic acids arise cyanohydrins ( lactic acid, mandelic acid, etc.).

In addition cyanohydrins play a role as intermediates in the benzoin addition and Kiliani Fischer synthesis.