Cyanohydrins are formed from carbonyl compounds by reactions mechanism:
Correct answer: C. Nucleophilic addition
- A. Free radical
- B. Nucleophilic substituion
- C. Nucleophilic addition
- D. Electrophilic addition
Explanation
As HCN is a nucleophile, it is added in a nucleophilic addition reaction. Hydrogen cyanide adds to aldehydes and ketones to form cyanohydrins. The reaction is carried out by slowly adding a mineral acid to an aqueous solution of sodium cyanide. The acid generates HCN from sodium cyanide in situ. The cyano group (-C≡N) is hydrolyzed by an aqueous acid into a carboxylic acid through an acid amide. This reaction is used in the synthesis of hydroxy acids that contain one more carbon atom than the number of carbon atoms in the starting aldehydes or ketones. The base-catalyzed nucleophilic addition reactions of aldehydes and ketones.
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About Aldehydes and Ketones
Aldehydes and ketones contain the polar carbonyl group, but aldehydes are generally more readily oxidised and more reactive than ketones. Coverage includes preparation by oxidation or reduction routes, nucleophilic addition of reagents such as hydrogen cyanide and bisulfite, and tests that distinguish aldehydes from ketones.
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