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NEET CHEMISTRYAldehydes, Ketones and Carboxylic AcidsHard

Question

In a basic medium, acetophenone yields a stable compound A with C2H5ONaC_2H_5ONa. The structure of A is:

A

Option 1 (Image Missing: Likely Dypnone/1,3-diphenyl-2-buten-1-one)

B

Option 2 (Image Missing)

C

Option 3: 4.

D

Option 4 (Image Missing)

Step-by-Step Solution

Acetophenone (C6H5COCH3C_6H_5COCH_3) contains α\alpha-hydrogens. In the presence of a strong base like sodium ethoxide (C2H5ONaC_2H_5ONa), it undergoes self-condensation (Aldol condensation).

  1. Enolate Formation: The base abstracts an α\alpha-proton from one molecule of acetophenone to form an enolate ion.
  2. Nucleophilic Attack: The enolate attacks the carbonyl carbon of another acetophenone molecule.
  3. Dehydration: The initial aldol product (eta-hydroxy ketone) loses a water molecule upon heating or in the stable basic medium to form an α,β\alpha,\beta-unsaturated ketone.

The final product is 1,3-Diphenyl-2-buten-1-one (common name: Dypnone).

Reaction: 2C6H5COCH3→C2H5ONaC6H5C(CH3)=CHCOC6H5+H2O2 C_6H_5COCH_3 \xrightarrow{C_2H_5ONa} C_6H_5C(CH_3)=CHCOC_6H_5 + H_2O

Exam Context & Concepts Covered

This question aligns with the NEET CHEMISTRY syllabus, specifically targeting concepts from Aldehydes, Ketones and Carboxylic Acids. Mastering this topic is crucial for scoring well in the upcoming medical entrance examinations. Solving conceptually related problems will help you understand the nuances of these concepts and improve your problem-solving speed.

CHEMISTRYAldehydes, Ketones and Carboxylic Acidsmediumacetophenoneyieldsstablecompound

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