Learn

Saturday, 31 October

JEE Main 2022 · ChemistryMultiple choiceDiagram basedMediumMulti-step

JEE Main 27 June 2022, Shift 2, Chemistry Q73

Question 73 of 90 in this shift, Chemistry question 13 of 30, Section A.

What will be the major product of following sequence of reactions? n−Bu−\mathrm{n-Bu-}[drawn: terminal triple bond] →(ii) Lindlar cat, H2(i) n-BuLi, n-C5H11Cl\xrightarrow[\text{(ii) Lindlar cat, H}_2]{\text{(i) n-BuLi, n-C}_5\text{H}_{11}\text{Cl}}

The figure, in words

Reaction scheme with drawn alkyne reactant; four options are drawn alkenes with C5H11 / n-Bu labels at different positions.
  1. (1)[figure: drawn C=C; left carbon has a bond down-left to H11C5\mathrm{H_{11}C_5}; right carbon has n-Bu at upper right and n-Bu at lower right]
  2. (2)[figure: drawn C=C; left carbon has a bond down-left to n-Bu; right carbon has n-Bu at upper right and a bond down to C5H11\mathrm{C_5H_{11}}]
  3. (3)[figure: drawn C=C at the bottom of a zigzag; H11C5\mathrm{H_{11}C_5} at top left and n-Bu at top right]Official answer
  4. (4)[figure: drawn C=C in a zigzag; C5H11\mathrm{C_5H_{11}} at top left and n-Bu at bottom right]

Official answer

Option 3

NTA final key.

Chapter
Hydrocarbons
Topic
Alkenes and Alkynes
Idea tested
Alkylation of Terminal Alkynes

Same idea in other shifts

Asked 2× in all
  1. 4 Sep 2020, Shift 2 · Q44The major product [R] in the following sequence of reactions is :…HardDiagram 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.