BRAINCAKEHydroxynitriles from Carbonyls
Aldehydes and ketones react with hydrogen cyanide, HCN, to form hydroxynitriles, which contain both an -OH group and a -C≡N group on the same carbon. A new carbon-carbon bond forms, so the chain gains one carbon atom.
Reagents: HCN is a very toxic gas, so in practice it is generated in the reaction mixture from sodium cyanide, NaCN(aq), and sulfuric acid, H2SO4(aq). This provides both CN− ions and H+ ions.
Mechanism: nucleophilic addition
1. The C=O bond is polar; the carbon is δ+. The cyanide ion's lone pair attacks this carbon, and the π-bond of C=O breaks, putting a negative charge on the oxygen.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
More in Carbon-Carbon Bond Formation
- Carbon-Carbon Bond Formation
- Nitriles from Haloalkanes
- Reduction of Nitriles to Amines
- Hydrolysis of Nitriles to Carboxylic Acids
- Extending Carbon Chains on Benzene
- Amides
- Naming Amides
All 8 lessons in Carbon-Carbon Bond Formation · All OCR A-level Organic Chemistry topics