Learn

Saturday, 31 October

JEE Main 2022 · ChemistryMultiple choiceSingle correctMediumApplication

JEE Main 24 June 2022, Shift 2, Chemistry Q75

Question 75 of 90 in this shift, Chemistry question 15 of 30, Section A.

Which of the following reagents / reactions will convert 'A' to 'B'?

The figure, in words

Reaction scheme with a right arrow. (A): six-membered ring with an H3C substituent on one ring carbon and, on the ring carbon directly opposite, a double bond to an exocyclic =CH2. (B): six-membered ring with H3C on one ring carbon and, on the opposite ring carbon, a CHO group. Labels (A) and (B) printed under the structures.
  1. (1)PCC oxidation
  2. (2)Ozonolysis
  3. (3)BH3_3, H2_2O2_2 / −^{-}OH followed by PCC oxidationOfficial answer
  4. (4)HBr, hydrolysis followed by oxidation by K2_2Cr2_2O7_7.

Official answer

Option 3

NTA final key.

Chapter
Aldehydes, Ketones and Carboxylic Acids
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. 15 Apr 2023, Shift 1 · Q76The product formed in the following multistep reaction is : CH3−CH=CH2\mathrm{CH_3-CH=CH_2}…MediumOtherHas 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.