Formation of Cyanohydrins and a-Aminonitriles

In the introduction to Chapter 9, it was mentioned that cyanide ions behave towards carbonyl compounds like the majority of O-, S- and Nnucleophiles. They add to the C=0 double bond. By taking up a proton the carbonyl oxygen is transformed into the OH group of a so-called cyanohydrin, i.e., a hydroxynitrile with geminal OH- and C=N groups. The classical transformation of this type is is effected by treatment of a carbonyl compound with both sodium 

The acetone cyanohydrin is employed as a solvent this means it is present in great excess. Under thermodynamic control this reaction preferentially leads to the formation of a cyanohydrin with an axial nitrile group and an equatorial OH group, since a nitrile group is smaller than an OH group. 

9 Additions of Heteroatom Nucleophiles to Carbonyl Compounds and Subsequent Reactions 

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