Learn

Friday, 9 October

JEE Main 2020 · ChemistryMultiple choiceDiagram basedHardApplication

JEE Main 8 January 2020, Shift 1, Chemistry Q45

Question 45 of 75 in this shift, Chemistry question 20 of 25, Section A.

The major product of the following reaction is : (CH3)2C=CH−CH2−CH2−C(CH3)=CH−CH2OH(\mathrm{CH_3})_2\mathrm{C{=}CH{-}CH_2{-}CH_2{-}C(CH_3){=}CH{-}CH_2OH} →dil. H2SO4\xrightarrow{\text{dil. }\mathrm{H_2SO_4}}

The figure, in words

Reactant is geraniol-type diene alcohol drawn as a skeletal structure: (CH3)2C=CH-CH2-CH2-C(CH3)=CH-CH2OH. Options are skeletal structures.
  1. (1)(CH3)2CH−CH(OH)−CH2−CH2−C(OH)(CH3)−CH2−CH2OH(\mathrm{CH_3})_2\mathrm{CH{-}CH(OH){-}CH_2{-}CH_2{-}C(OH)(CH_3){-}CH_2{-}CH_2OH}
  2. (2)[figure: cyclohexene ring with a methyl on the sp2 carbon and a C(OH)(CH3)2\mathrm{C(OH)(CH_3)_2} group at the position para to it (alpha-terpineol skeleton)]Official answer
  3. (3)[figure: cyclopentane ring bearing a methyl, a vinyl group and a C(OH)(CH3)2\mathrm{C(OH)(CH_3)_2} group on adjacent/ring carbons]
  4. (4)(CH3)2C(OH)−CH2−CH2−C(OH)(CH3)−CH2−CH2OH(\mathrm{CH_3})_2\mathrm{C(OH){-}CH_2{-}CH_2{-}C(OH)(CH_3){-}CH_2{-}CH_2OH}

Official answer

Option 2

NTA final key (Jan 2020).

Chapter
Alcohols, Phenols and Ethers
Topic
No close match in our taxonomy
Idea tested
No close match in our taxonomy

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.