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Saturday, 31 October

JEE Main 2023 · ChemistryMultiple choiceOtherMediumMulti-step

JEE Main 15 April 2023, Shift 1, Chemistry Q76

Question 76 of 90 in this shift, Chemistry question 16 of 30, Section A.

The product formed in the following multistep reaction is : CH3−CH=CH2\mathrm{CH_3-CH=CH_2} →iii) PCC  iv) CH3MgBri) B2H6  ii) H2O2, NaOH\xrightarrow[\text{iii) PCC}\;\text{iv) }\mathrm{CH_3MgBr}]{\text{i) }\mathrm{B_2H_6}\;\text{ii) }\mathrm{H_2O_2,\,NaOH}}

The figure, in words

Reaction arrow from propene with reagents: i) B2H6, ii) H2O2, NaOH, iii) PCC, iv) CH3MgBr.
  1. (1)(CH3)3C−OH\mathrm{(CH_3)_3C-OH} (drawn as CH3−C(OH)(CH3)−CH3\mathrm{CH_3-C(OH)(CH_3)-CH_3})
  2. (2)CH3−CH2−CH(OH)−CH3\mathrm{CH_3-CH_2-CH(OH)-CH_3}Official answer
  3. (3)CH3−CH2−C(=O)−OCH3\mathrm{CH_3-CH_2-C(=O)-OCH_3}
  4. (4)CH3−CH2−CH2−CH2−OH\mathrm{CH_3-CH_2-CH_2-CH_2-OH}

Official answer

Option 2

NTA final key.

Chapter
Alcohols, Phenols and Ethers
Topic
Alkenes and Alkynes
Idea tested
Hydroboration-Oxidation

Same idea in other shifts

Asked 6× in all
  1. 4 Apr 2024, Shift 2 · Q79CH3−CH2−CH2−Br+NaOH→C2H5OH\mathrm{CH_3-CH_2-CH_2-Br + NaOH \xrightarrow{C_2H_5OH}} Product 'A' Product A →H2O/H+\xrightarrow{\mathrm{H_2O/H^+}} Product "B" Product A…EasySingle correct
  2. 9 Apr 2024, Shift 1 · Q76Identify the product A and product B in the following set of reactions. [figure: CH3−CH=CH2\mathrm{CH_3-CH=CH_2}…EasySingle correctHas a figure
  3. 10 Apr 2023, Shift 2 · Q75Incorrect method of preparation for alcohols from the following is:EasySingle correct
  4. 24 Jun 2022, Shift 2 · Q75Which of the following reagents / reactions will convert 'A' to 'B'?MediumSingle correctHas a figure
  5. 8 Jan 2020, Shift 2 · Q45The major product [B] in the following sequence of reactions is :…MediumDiagram basedHas 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.