Which of the following does not give aldol condensation?
Correct answer: A. Methanol
- A. Methanol
- B. Ethanal
- C. Propanone
- D. 2-pentanone
Explanation
Aldol condensation is a reaction shown by aldehydes and ketones containing at least one α-hydrogen atom in the presence of dilute base. In this reaction, the enolate ion formed from the compound attacks the carbonyl carbon of another molecule, producing a β-hydroxy aldehyde or ketone, which may further dehydrate to give an α,β-unsaturated product. Compounds that lack α-hydrogen cannot undergo aldol condensation.Example: When two molecules of ethanal react in the presence of dilute NaOH 2CH3CHO→CH3CH(OH)CH2CHO→ΔCH3CH=CHCHOThe product formed is Crotonaldehyde, an α,β-unsaturated aldehyde.Explanation:The correct answer is A, Methanol. Aldol condensation is a reaction of aldehydes and ketones having at least one α-hydrogen atom. As, alcohols do not have a carbonyl group, so they do not undergo aldol condensation.
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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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