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

38 questions on Catalytic hydrogenation and metal hydride reductions (LiAlH4, NaBH4, DIBAL) from the Reduction, Oxidation and Hydrolysis in Organic Chemistry chapter: 8 NEET level, 15 JEE Main, 15 JEE Advanced. Each one opens with its answer and solution.

• Ethyl acetate is converted into ethanol (two moles per mole of ester) by which reagent? NEET level
• Hydrogenation of CH3-C#C-CH3 with H2 over Lindlar catalyst gives mainly NEET level
• Acetophenone, C6H5-CO-CH3, on treatment with NaBH4 in methanol followed by water gives NEET level
• The Rosenmund reduction converts benzoyl chloride into NEET level
• Methyl pent-4-enoate, CH2=CH-CH2-CH2-COOCH3, is shaken with H2 (1 atm) over Pd-C at room temperature until uptake stops. The product is JEE Main level
• Propyl benzyl ether, C6H5CH2-O-CH2CH2CH3, is stirred with H2 and Pd-C. The organic products are JEE Main level
• 2,2-Dimethyloxirane (isobutylene oxide) is treated with LiAlH4 in ether and then with dilute acid. The major product is JEE Main level
• One mole of methyl 5-phenylpent-4-en-2-ynoate, C6H5-CH=CH-C#C-COOCH3, is hydrogenated with H2 (1 atm) over Pd-C at room temperature until no more gas is absorbe... JEE Main level
• Which reagent converts phenylacetonitrile, C6H5CH2-CN, into 2-phenylethanamine, C6H5CH2CH2NH2? JEE Main level
• Which of the following are reduced by NaBH4 in methanol at 0 degC to the corresponding alcohol? JEE Main level
• Excess LiAlH4 in ether followed by aqueous acid work-up gives propan-1-ol as one of the organic products from which of the following? JEE Main level
• Ethyl 3-oxobutanoate, CH3-CO-CH2-COOC2H5, is treated first with NaBH4 in methanol at 0 degC, and the product is then treated with excess LiAlH4 in ether followe... JEE Advanced level
• Count the number of hydride ions (H-) that must be delivered by LiAlH4 to convert one molecule of 4-cyanobenzoic acid, NC-C6H4-COOH, completely to the aluminium... JEE Advanced level
• Ethyl (E)-3-phenylprop-2-enoate (ethyl cinnamate) is subjected to the sequence: (i) H2 (1 mol), Pd-C, room temperature; (ii) DIBAL-H (1 equivalent), -78 degC, t... JEE Advanced level
• Assertion (A): DIBAL-H at -78 degC converts ethyl pentanoate into pentanal after aqueous work-up, whereas LiAlH4 gives pentan-1-ol. Reason (R): With DIBAL-H at ... JEE Advanced level
• Cyclohex-2-en-1-one is treated successively with (i) NaBH4/CeCl3 in methanol (1,2-reduction), (ii) H2, Pd-C, (iii) PCC in CH2Cl2. The final product is JEE Advanced level
• Benzonitrile is treated with (i) DIBAL-H (1 equivalent) in toluene at -78 degC, then aqueous work-up; the product is heated with (ii) N2H4, KOH, ethylene glycol... JEE Advanced level
• Methyl 4-acetylbenzoate is CH3CO-C6H4-COOCH3 (substituents at positions 1 and 4 of the benzene ring). Which statements are correct? JEE Advanced level
• 5-Methoxypent-2-yne is CH3-C#C-CH2CH2-O-CH3. Which statements are correct? JEE Advanced level
• Reduction of ethyl ethanoate, CH3-COOC2H5, with excess LiAlH4 in dry ether followed by H3O+ gives NEET level
• Hydrogenation of but-2-yne over Lindlar catalyst (Pd on CaCO3 poisoned with quinoline) gives mainly NEET level
• In the Rosenmund reduction, benzoyl chloride is converted into benzaldehyde by NEET level
• Which reagent converts the carbonyl group of acetophenone into a CH2 group under strongly basic conditions? NEET level
• 4-Nitroacetophenone is treated with NaBH4 in methanol at room temperature. The major product is JEE Main level
• One equivalent of H2 is added to 4-phenylbut-3-en-2-one, C6H5-CH=CH-CO-CH3, over Pd-C at 1 atm and room temperature. The major product is JEE Main level
• Hex-3-yne is converted separately by (i) H2/Lindlar catalyst and (ii) Na in liquid NH3. The main products are respectively JEE Main level
• Benzyl acetate, CH3COOCH2C6H5, is stirred under H2 (1 atm) with Pd-C at room temperature until reaction stops. The products are JEE Main level
• 1,2-Epoxypropane (methyloxirane) is treated with LiAlH4 in ether followed by H3O+. The product is JEE Main level
• N-Methylethanamide, CH3-CO-NH-CH3, is heated with excess LiAlH4 in ether and then treated with water. The product is JEE Main level
• Which ketone is best converted into the corresponding CH2 compound by Wolff-Kishner reduction (N2H4, KOH, ethylene glycol, heat), but is unsuitable for Clemmens... JEE Main level
• 1.00 mol of 4-nitrocinnamaldehyde, O2N-C6H4-CH=CH-CHO (nitro group on the ring para to the side chain), is hydrogenated with excess H2 over Pd-C at 1 atm and ro... JEE Main level
• Ethyl 4-acetylbenzoate, CH3CO-C6H4-COOC2H5 (para), is treated with (i) NaBH4 in methanol and, in a separate experiment, (ii) excess LiAlH4 in ether followed by ... JEE Advanced level
• Methyl 3-cyanopropanoate, NC-CH2CH2-COOCH3, is reduced with excess LiAlH4 followed by aqueous work-up. Count only hydride ions delivered to carbon atoms of the ... JEE Advanced level
• Pent-3-yn-1-ol, CH3-C#C-CH2CH2OH, is treated first with Na in liquid NH3 and the product is then oxidised with PCC in CH2Cl2 (no isomerisation of the double bon... JEE Advanced level
• Which of the following transformations by NaBH4 in methanol at room temperature are correctly described? JEE Advanced level
• Excess LiAlH4 in dry ether, followed by H3O+ work-up, is used. Which conversions are correct? JEE Advanced level
• Which statements about the stated catalytic hydrogenation are correct? JEE Advanced level
• Select the correct choices of method for converting the carbonyl group into CH2 in the substrate named. JEE Advanced level