NEET 2023 Phase 1 · ChemistryCarbonyl reductionPrevious Year Question

Identify the product (A) in the following reaction. The substrate is 1-(4-acetylphenyl)ethan-1-one type compound bearing two $- COCH X_{3}$ (acetyl) groups, treated with $Zn - Hg$ / conc. $HCl$ : $substrate Zn - Hg conc \cdot HCl A + 2 H X_{2} O$

Answer: (A) (A) Both $- COCH X_{3}$ groups reduced to $- CH X_{2} CH X_{3}$ (ethyl). \textbf{Answer:} (A) Both acetyl groups reduced to ethyl ( $- CH X_{2} CH X_{3}$ ).

A.(A) Both $- COCH X_{3}$ groups reduced to $- CH X_{2} CH X_{3}$ (ethyl)✓
B.(B) Both groups reduced to $- CH (OH) CH X_{3}$ (secondary alcohols)
C.(C) One $- CH (OH) X^{-}$ and one $- CH X_{2} OH$ group
D.(D) Both groups replaced by $- CH X_{3}$ (methyl)

Correct Answer

(A) (A) Both $- COCH X_{3}$ groups reduced to $- CH X_{2} CH X_{3}$ (ethyl)

Solution & Explanation

\textbf{Answer:} (A) Both acetyl groups reduced to ethyl ( $- CH X_{2} CH X_{3}$ ). \textbf{Solution:} $Zn - Hg$ with conc. $HCl$ is the Clemmensen reduction, which converts the carbonyl ( $> C = O$ ) of aldehydes and ketones completely to a methylene ( $- CH X_{2} -$ ) group, releasing water (here $2 H X_{2} O$ for the two carbonyls). Each $- CO - CH X_{3}$ group is therefore reduced to $- CH X_{2} - CH X_{3}$ , giving the fully reduced hydrocarbon with two ethyl substituents.

🎯

43,000+ questions in हिंदी & English · one-tap toggle

Practice NEET 2023 Phase 1 Chemistry — free, with instant solutions

The app builds a daily goal from your weak topics and brings each question back just before you forget it — so what you solve today turns into marks on exam day.

Open →📚Practice all NEET Chemistry PYQs chapter-wise →💡Don't get it? Learn the Aldehydes, Ketones And Carboxylic Acid concepts →

← Chemistry Q4 Chemistry Q6 →

More NEET PYQ solutions

ChemIdentify the suitable reagent for the following conversion: C6H5COOCH3 -> C6H5CHO (methyl benzoate to benzaldehyde)ChemThe major product of the following reaction is: 4-oxo-4-phenylbutanenitrile C6H5-CO-CH2-CH2-CN is treated with (i) CH3MgBr (excess) and then (ii) H3O+.ChemThe major product formed in the following conversion is: A cyclopentanone bearing a -CH2COCH3 (2-oxopropyl) side chain treated with (i) NaBH4, then (ii) H2SO4, heat.ChemIdentify X in the following reactions: R-COOH ->[(i) X][(ii) H2O/HCl] R-CH2OH R-CH=CH2 ->[(i) X][(ii) H2O, NaOH, H2O2] R-CH2-CH2-OH ChemIdentify the final product [D] in the following sequence: CH3CHO ->[(i) LiAlH4][(ii) H3O+] [A] ->[H2SO4][ ] [B] ->[HBr] [C] ->[C6H5Br, Na][dry ether] [D]ChemWhat is the IUPAC name of the organic compound formed in the following reaction? CH3COCH3 ->[(i) C2H5MgBr, dry ether][(ii) H2O, H+] Product ChemThe product formed in the following reaction is: 4-methyl-2-(2-methoxy-2-oxoethyl)cyclohexan-1-one ->[NaBH4][C2H5OH] ? (A cyclohexanone ring bearing a -CH2COOCH3 methyl-ester side chain and a CH3 substituent.)ChemThe reaction between acetone (CH3COCH3) and methylmagnesium chloride (CH3MgCl) followed by hydrolysis gives

More: All NEET 2023 Phase 1 Chemistry PYQs · NEET Chemistry PYQs · All NEET PYQs · Previous year papers

Identify the product (A) in the following reaction. The substrate is 1-(4-acetylphenyl)ethan-1-one type compound bearing two −COCHX3​ (acetyl) groups, treated with Zn−Hg / conc. HCl: substrateZn−Hgconc⋅HCl​A+2HX2​O

Solution & Explanation

More NEET PYQ solutions

Identify the product (A) in the following reaction. The substrate is 1-(4-acetylphenyl)ethan-1-one type compound bearing two $- COCH X_{3}$ (acetyl) groups, treated with $Zn - Hg$ / conc. $HCl$ : $substrate Zn - Hg conc \cdot HCl A + 2 H X_{2} O$