Which ketone is best converted into the corresponding CH2 compound by Wolff-Kishner reduction (N2H4, KOH, ethylene glycol, heat), but is unsuitable for Clemmensen reduction (Zn-Hg, conc. HCl)?

4-phenylacetophenone (4-acetylbiphenyl)

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JEE Main levelSingle correct optionDifficulty 2 of 3ro121

Which ketone is best converted into the corresponding $CH X_{2}$ compound by Wolff-Kishner reduction ( $N X_{2} H X_{4}$ , KOH, ethylene glycol, heat), but is unsuitable for Clemmensen reduction (Zn-Hg, conc. $HCl$ )?

Aethyl 4-oxopentanoate
B4-phenylacetophenone (4-acetylbiphenyl)
C4-tert-butoxyacetophenone
D4-chloroacetophenone

Answer: C

An aryl tert-butyl ether is cleaved by hot conc. HCl, so Clemmensen conditions are unsuitable but the ether survives KOH. 4-Acetylbiphenyl and 4-chloroacetophenone tolerate both methods. Ethyl 4-oxopentanoate is the reverse case: the ester is saponified by KOH, so Wolff-Kishner is unsuitable.

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Which ketone is best converted into the corresponding CHX2​ compound by Wolff-Kishner reduction (NX2​HX4​, KOH, ethylene glycol, heat), but is unsuitable for Clemmensen reduction (Zn-Hg, conc. HCl)?

Answer: C

More questions on Catalytic hydrogenation and metal hydride reductions (LiAlH4, NaBH4, DIBAL)

Which ketone is best converted into the corresponding $CH X_{2}$ compound by Wolff-Kishner reduction ( $N X_{2} H X_{4}$ , KOH, ethylene glycol, heat), but is unsuitable for Clemmensen reduction (Zn-Hg, conc. $HCl$ )?