What is produced when HCN reacts with carbonyl compounds in the presence of sulfuric acid?

When hydrogen cyanide (HCN) reacts with carbonyl compounds such as aldehydes or ketones in the presence of sulfuric acid, the primary product formed is hydroxynitriles. This reaction is a nucleophilic addition mechanism where the cyanide ion (CN-) adds to the carbonyl carbon, which is electrophilic.

In this process, sulfuric acid acts as a catalyst and helps to protonate the carbonyl oxygen, making it more positive and increasing its susceptibility to nucleophilic attack. The cyanide ion then attacks the carbonyl carbon, leading to the formation of a tetrahedral intermediate. Subsequently, the reaction involves proton transfer, ultimately resulting in the formation of hydroxynitrile, which is characterized by the presence of both a hydroxyl group (-OH) and a nitrile group (-C≡N).

This process is specific and does not produce carboxylic acids, esters, or amines under these conditions. Carboxylic acids and esters typically require further chemical progression or additional reagents beyond what is involved in the direct reaction with HCN and carbonyls. Amines would also not be formed directly from this reaction as the starting materials do not include amine functionalities. Thus