Racemic mandelonitrile may be prepared similar to many other cyanohydrins. Formation of cyanohydrins from carbonyl compounds renders the former carbonyl carbon acidic. Some nitriles, which occur naturally as cyanohydrins, release hydrogen cyanide. The cyanohydrins are a special class of nitriles. It catalyzes the addition of trimethylsilyl cyanide (TMSCN) to aldehydes to form cyanohydrins. Because ester protecting groups are base labile, mild bases must be employed with ester-protected cyanohydrins. Cyanohydrins are intermediates in the Strecker amino acid synthesis. Cyanohydrins are sources of highly toxic hydrogen cyanide. Cyanohydrins are industrially important precursors to carboxylic acids and some amino acids. After protection of the hydroxyl group, cyanohydrins can function essentially as masked acyl anions.