Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Aldehydes Ketones and Carboxylic Acids question

2023 · 31 Jan · Shift 2 · Q2
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Chemistry
  4. /Aldehydes Ketones and Carboxylic Acids
  5. /2023 · 31 Jan · Shift 2 · Q2

Aldehydes Ketones and Carboxylic Acids question

2023 · 31 Jan · Shift 2 · Q2

JEE MainChemistryAldehydes Ketones and Carboxylic AcidsMCQ+4 / −1
Cyclohexylamine when treated with nitrous acid yields (P)(\mathrm{P})(P). On treating (P)(\mathrm{P})(P) with PCC\mathrm{PCC}PCC results in (Q). When (Q)(\mathrm{Q})(Q) is heated with dil. NaOH\mathrm{NaOH}NaOH we get (R)(\mathrm{R})(R) The final product (R) is :
  1. A
    JEE Main 2023 (Online) 31st January Evening Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 85 English Option 1
  2. B
    JEE Main 2023 (Online) 31st January Evening Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 85 English Option 2
  3. C
    JEE Main 2023 (Online) 31st January Evening Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 85 English Option 3
  4. D
    JEE Main 2023 (Online) 31st January Evening Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 85 English Option 4
View written solutionFree

Correct answer: B

  1. Reaction of cyclohexylamine with nitrous acid

Cyclohexylamine is a primary aliphatic amine. Primary aliphatic amines react with nitrous acid to form the corresponding alcohol:

C6H11NH2→0−5∘CHNO2C6H11OH+N2+H2O\mathrm{C_6H_{11}NH_2} \xrightarrow[0-5^\circ C]{HNO_2} \mathrm{C_6H_{11}OH} + N_2 + H_2OC6​H11​NH2​HNO2​0−5∘C​C6​H11​OH+N2​+H2​O

So,

P=cyclohexanolP = \text{cyclohexanol}P=cyclohexanol
  1. Oxidation of }P\text{ with PCC

PCC oxidizes a secondary alcohol to a ketone. Cyclohexanol is a secondary alcohol, so:

cyclohexanol→PCCcyclohexanone\text{cyclohexanol} \xrightarrow{PCC} \text{cyclohexanone}cyclohexanolPCC​cyclohexanone

Thus,

Q=cyclohexanoneQ = \text{cyclohexanone}Q=cyclohexanone
  1. Heating }Q\text{ with dilute NaOH

Cyclohexanone has α\alphaα-hydrogens, so in dilute NaOH it undergoes aldol condensation (self-condensation).

First, one molecule forms the enolate and attacks another molecule of cyclohexanone to give the β\betaβ-hydroxy ketone. On heating, dehydration occurs to form the α,β\alpha,\betaα,β-unsaturated ketone.

The product is:

2-cyclohexylidenecyclohexanone\text{2-cyclohexylidenecyclohexanone}2-cyclohexylidenecyclohexanone

This is the self-aldol condensation product of cyclohexanone.

  1. Final answer

Therefore,

R=2-cyclohexylidenecyclohexanoneR = \text{2-cyclohexylidenecyclohexanone}R=2-cyclohexylidenecyclohexanone

So the correct option is B.

PreviousNext

More from Aldehydes Ketones and Carboxylic Acids

  • Two statements are given below : Statement I : The melting point of monocarboxylic acid with even number of carbon atoms is higher than that of with odd number of carbon atoms acid immediately below and above it in the series. Statement II…2022 · MCQ
  • In the given reaction The number of chiral carbon/s in product A is ​. Includes diagram2022 · Numerical
  • Which one of the following reactions does not represent correct combination of substrate and product under the given conditions?2022 · MCQ
  • CH3​−CH2​−CNEther⟶CH3​MgBr​AH3​O+​BHCl⟶Zn−Hg​C The correct structure of C is2022 · MCQ
  • What is the major product of the following reaction? Includes diagram2022 · MCQ
  • Which of the following conditions or reaction sequence will NOT give acetophenone as the major product?2022 · MCQ
  • The products formed in the following reaction, A and B are Includes diagram2022 · MCQ
  • Consider the above reaction and predict the major product. Includes diagram2022 · MCQ