IIT-JEE 2007 · Paper 2 · Chemistry Q26

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ChemistrySingle correct+3 / -1Question 26 of 66

Cyclohexene on ozonolysis followed by reaction with zinc dust and water gives compound E. Compound E on further treatment with aqueous KOH yields compound F. Compound F is

Cyclopent-1-ene-1-carbaldehyde: CHO on a ring carbon of the C=C double bond.

Cyclopent-2-ene-1-carbaldehyde: CHO on an sp³ ring carbon next to the C=C double bond.

Cyclopent-2-ene-1-carboxylic acid: COOH on an sp³ ring carbon next to the C=C double bond.

Hexanedioic (adipic) acid drawn as a bent chain HO₂C-(CH₂)₄-CO₂H.

Answer and worked solution

Official answer: A

Ozonolysis. Cyclohexene opens to hexane-1,6-dial, $\ce{OHC(CH2)4CHO}$ (E).

Intramolecular aldol. With aqueous KOH, the enolate at C2 attacks the other CHO (C6), closing a five-membered ring; dehydration gives the conjugated enal:
$\text{F}=\text{cyclopent-1-ene-1-carbaldehyde}.$

(A)

Topics:Aldol and related condensations Alkenes

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IIT-JEE 2007 · Paper 2, Chemistry question 26