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Clemmensen reduction of a ketone is carried out in the presence of which of the following?
A
$H_2$ and Pt as catalyst
B
Glycol with KOH
C
Zn-Hg with HCl
D
$LiAlH_4$
Detailed Solution
In the Clemmensen reduction, the carbonyl group of an aldehyde or ketone is reduced to a methylene ($-CH_2-$) group.
The reagent is zinc amalgam and concentrated hydrochloric acid: $>C=O \xrightarrow{Zn-Hg/HCl} >CH_2 + H_2O$
Hydrazine followed by KOH in ethylene glycol is the Wolff–Kishner reduction.
$H_2$/Pt and $LiAlH_4$ reduce a ketone only to a secondary alcohol.
Hence Clemmensen reduction is carried out with Zn-Hg and HCl.
The reagent is zinc amalgam and concentrated hydrochloric acid: $>C=O \xrightarrow{Zn-Hg/HCl} >CH_2 + H_2O$
Hydrazine followed by KOH in ethylene glycol is the Wolff–Kishner reduction.
$H_2$/Pt and $LiAlH_4$ reduce a ketone only to a secondary alcohol.
Hence Clemmensen reduction is carried out with Zn-Hg and HCl.