Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main20265 April 2026Morning ShiftChemistryHydrocarbonsActual

"P" is a hydrocarbon of molecular formula: C ₈ H ₁₄ . On ozonolysis, "P" forms "Q". "Q" on treatment with alkali under reflux condition produces "R", which on treatment with I ₂ /NaOH gives a yellow precipitate. Acidification of the solution gives "S". The structure of "S" is given below: The correct structure of "P" is

Correct answer

3

Step-by-step solution

The structure of "S" is 2-methylcyclopent-1-ene-1-carboxylic acid. Since "S" is obtained by the acidification of the product from the iodoform reaction of "R", "R" must contain a methyl ketone group ( -COCH₃ ). The iodoform reaction converts the -COCH₃ group into a -COOH group alongside the formation of a yellow precipitate of iodoform ( CHI₃ ). Therefore, the structure of "R" is 1-acetyl-2-methylcyclopentene. "R" is formed by the intramolecular aldol condensation of "Q". Performing a retro-aldol condensation on "R

Practice Hydrocarbons on Quantrex Academy →

More from Hydrocarbons

In the following reaction sequence, Q , R , S and T are the major products. The correct statement(s) about Q , R , S and T is(are) 2026Treatment of buta-1,3-diyne with NaNH ₂ ( 2 equivalents), followed by reaction with excess of trans - CH ₃ -CH=CH-CH ₂ -Br gives X as the major product. The maximum number of carbo 2026The List-II contains products obtained from the reaction of compounds in List-I with O ₃ /Zn- H ₂ O followed by cyclization (via more stable enolate) in the presence of aqueous NaO 2026Natural rubber on complete ozonolysis ( O ₃ /Zn- H ₂ O ) gives compound X as the major product. X gives positive iodoform and Tollen's tests. X on heating with aqueous NaOH gives Y 2026An optically active alkyl bromide C₄ H₉ Br, reacts with ethanolic KOH to form major compound [A] which reacts with bromine to give compound [B]. Compound [B] reacts with ethanolic 2026An alkane (Y) requires 8 moles of oxygen for complete combustion and on chlorination with Cl₂ /h , (Y) gives only one monochlorinated product (Z) . The total number of primary carb 2026R_f value for 2 -methylpropene in a solvent system (Ethyl acetate + ether) is 0.42 . 2 -methylpropene is treated with dilute H ₂ SO ₄ to give major organic product (X). R_f value f 2026Given below are two statements: Statement I: Methane can be prepared by decarboxylation of sodium ethanoate, Kolbe's electrolysis of sodium acetate and reaction of CH ₃ MgBr with w 2026 Full Hydrocarbons list All JEE Main PYQs