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ChemistryCarbonyl compoundsMiscellaneous/MixedEasy2 minPYQ_2023
ChemistryEasysingle choice

Match List I with List II.

List IList II
ReactionReagents
(A)Hoffmann
Degradation
(I)Conc.KOH,Δ
(B)Clemmensen
reduction
(II)CHCl3,NaOH/H3O+
(C)Cannizzaro reaction(III)Br2,NaOH
(D)Reimer-Tiemann
reaction
(IV)Zn-Hg/HCl

Options:

Answer:
C
Solution:

(A) Hoffmann degradation reaction: Hoffmann developed a method for the preparation of primary amines by treating an amide with bromine in an aqueous or ethanolic solution of sodium hydroxide. 

       O             R-C-NH2 + Br2 + 4NaOH  R-NH2 + Na2CO3 + 2NaBr + 2H2O

(B) Clemmensen reduction reaction: The Clemmensen reduction is a reaction that is used to reduce aldehydes or ketones to alkanes using hydrochloric acid and zinc amalgam.

(C) Cannizzaro reaction: Aldehydes which do not have an α-hydrogen atom, undergo self-oxidation and reduction (disproportionation) reaction on heating with concentrated alkali.

(D) Reimer-Tiemann reaction: On treating phenol with chloroform in the presence of sodium hydroxide, a –CHO group is introduced at ortho position of benzene ring. This reaction is known as Reimer-Tiemann reaction.

So, the correct matching is given in the following table:

Reactions Reagent used
(A) Hoffmann degradationBr2/NaOH
(B) Clemmensen reductionZn-Hg/HCl
(C) Cannizzaro reactionconc.KOH/ KOH/
(D) Reimer-Tiemann reactionCHCl3,NaOH/H3O+
Stream:JEESubject:ChemistryTopic:Carbonyl compoundsSubtopic:Miscellaneous/Mixed
2mℹ️ Source: PYQ_2023

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