Cannizzaro's reaction is not given by
Correct answer: B. acetaldehyde
- A. formaldehyde
- B. acetaldehyde
- C. benzaldehyde
- D. trimethly acetaldehyde
Explanation
Cannizzaro's reaction requires aldehydes without an α-hydrogen, the hydrogen atom directly attached to the carbon next to the carbonyl group. The lack of this α-hydrogen prevents an alternative reaction pathway - aldol condensation - from dominating.Acetaldehyde, CH3CHO, possesses an α-hydrogen. This makes it readily undergo aldol condensation instead of Cannizzaro's reaction. In aldol condensation, two acetaldehyde molecules combine to form a hydroxyaldehyde or β-hydroxyaldehyde.
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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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