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Saturday, 31 October

JEE Main 2021 · ChemistryMultiple choiceDiagram basedMediumApplication

JEE Main 22 July 2021, Shift 2, Chemistry Q46

Question 46 of 90 in this shift, Chemistry question 16 of 30, Section A.

Which one of the following compounds will provide a tertiary alcohol on reaction with excess of CH3MgBr\mathrm{CH_3MgBr} followed by hydrolysis ?

The figure, in words

All four options are drawn structures; descriptions are of atoms/groups as drawn.
  1. (1)[figure: benzene ring with a C(=O)CH3 group (C=O drawn with O above, CH3 to the right) at the upper right and OH at the lower left]
  2. (2)[figure: benzene ring bonded to O, which is bonded to C(=O)CH3 (the C=O oxygen drawn below)]Official answer
  3. (3)[figure: bicyclic structure of a benzene ring fused to a six-membered ring carrying two C=O groups, one at top and one at bottom, with one C=C in the second ring]
  4. (4)[figure: benzene ring with NC at left, a C≡CH group below, and a CH2OCH2CH3 group at upper right]

Official answer

Option 2

NTA final key.

Chapter
Alcohols, Phenols and Ethers
Topic
Carboxylic Acids and Derivatives
Idea tested
Reaction of Esters with Grignard Reagents

Same idea in other shifts

Asked 4× in all
  1. 9 Apr 2024, Shift 2 · Q79Major product of the following reaction is [figure: 4-cyanophenyl methyl ester, i.e. benzene ring with CN at one para position and…MediumSingle correctHas a figure
  2. 27 Aug 2021, Shift 2 · Q45Given below are two statements : Statement I : Ethyl pent-4-yn-oate on reaction with CH3MgBr\mathrm{CH_3MgBr} gives a 3∘3^\circ-alcohol.…MediumTwo statements
  3. 2 Apr 2017 (offline) · Q59The correct sequence of reagents for the following conversion will be : [reaction: 4-formylcyclohexanone (ring bearing C=O at the top and…HardSingle correctHas a figure

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 108 of the 174 JEE Main shifts held from 2017 to 2026.