Use
cyanohydrins: Organic compoundsformed by the addition of hydrogencyanide to aldehydes or ketones (inthe presence of a base). The first stepis attack by a CN– ion on the carbonylcarbon atom. The final productis a compound in which a -CN and-OH group are attached to the samecarbon atom. For example, ethanalreacts as followsCH3CHO + HCN → CH3CH(OH)(CN)The product is 2-hydroxypropanonitrile.Cyanohydrins of this type canbe oxidized to α-hydroxy carboxylicacids.