Preparation of alcohols including from carbonyls and Grignard

37 questions on Preparation of alcohols including from carbonyls and Grignard from the Alcohols, Phenols and Ethers chapter: 8 NEET level, 15 JEE Main, 14 JEE Advanced. Each one opens with its answer and solution.

• Propan-2-ol is obtained when CH3MgBr is treated with which carbonyl compound, followed by H3O+? NEET level
• Hydroboration-oxidation (BH3 in THF, then H2O2/NaOH) of propene gives mainly NEET level
• Reaction of ethylene oxide with CH3MgBr in dry ether, followed by H3O+, gives NEET level
• In the fermentation of sugar to ethanol, the enzyme that converts glucose into ethanol and carbon dioxide is NEET level
• (CH3)3C-CH=CH2 (3,3-dimethylbut-1-ene) is heated with dilute aqueous H2SO4. The major alcohol formed is JEE Main level
• 3,3-Dimethylbut-1-ene is treated with Hg(OAc)2 in THF/H2O, followed by NaBH4. The major product is JEE Main level
• Ethyl propanoate is treated with excess LiAlH4 in dry ether, followed by H3O+. The organic products are JEE Main level
• Ethyl acetate is treated with excess C2H5MgBr and then with H3O+. The alcohol derived from the acyl part of the ester is JEE Main level
• Methyl 4-acetylbenzoate is treated with NaBH4 in ethanol at room temperature, and then with dilute acid work-up. The product is JEE Main level
• Methyl 4-hydroxy-3-(hydroxymethyl)benzoate is treated with a large excess of CH3MgBr in dry ether (before H3O+ work-up). Count the moles of CH3MgBr consumed per... JEE Main level
• Which of the following sequences give a primary alcohol as the major product after the final aqueous work-up? JEE Main level
• 1-Methylcyclohexene is subjected to hydroboration with BH3/THF and then H2O2/NaOH. The major product (racemic) is JEE Advanced level
• An ester of formula C4H8O2 is treated with excess CH3MgBr and then H3O+. The only organic product is propan-2-ol. The ester is JEE Advanced level
• 2-Methyloxirane (propylene oxide) is treated separately with (I) CH3ONa in CH3OH, and (II) CH3OH with a catalytic amount of H2SO4. The major products are, respe... JEE Advanced level
• Acetone is treated with C2H5MgBr and then H3O+; the product is heated with conc. H2SO4 to give the major (Saytzeff) alkene; this alkene is then treated with BH3... JEE Advanced level
• Which of the following methods give 2-methylpropan-2-ol (tert-butyl alcohol) as the major product? JEE Advanced level
• Which statements about hydride reductions are correct? JEE Advanced level
• Ethyl methanoate (HCOOC2H5) is treated with excess CH3MgBr in dry ether and then with H3O+. Which of the following are formed? JEE Advanced level
• Acid-catalysed hydration of propene (dilute H2SO4, then water) gives mainly which alcohol? NEET level
• Ethylmagnesium bromide, C2H5MgBr, is allowed to react with methanal (HCHO) and the adduct is then hydrolysed with H3O+. The alcohol formed is NEET level
• Propanone is treated with CH3MgBr and the product is hydrolysed with H3O+. The alcohol obtained is NEET level
• Which of the following reagents converts ethanoic acid, CH3COOH, into ethanol? NEET level
• Methyl propanoate, CH3CH2COOCH3, is treated with excess CH3MgBr and then H3O+. The organic alcohol product is JEE Main level
• 3,3-Dimethylbut-1-ene is treated with Hg(OAc)2 in water/THF, followed by NaBH4. The major product is JEE Main level
• Methyloxirane (propylene oxide) is treated with CH3MgBr in dry ether and then with H3O+. The product is JEE Main level
• 1-Methylcyclohexene undergoes hydroboration with BH3 in THF, followed by H2O2/NaOH. The major product is JEE Main level
• In which of the following does hydrolysis (or work-up) give a primary alcohol as (at least one of) the alcohol product(s)? JEE Main level
• NaBH4 in ethanol at room temperature reduces which of the following to the corresponding alcohol? JEE Main level
• Assertion (A): 1-Chloropropane gives mainly propan-1-ol with aqueous KOH but mainly propene with alcoholic KOH. Reason (R): Alcoholic KOH contains the alkoxide ... JEE Main level
• 3-Methylbut-1-ene is hydrated with dilute H2SO4 (acid-catalysed hydration). The major alcohol is JEE Main level
• Methyl 7-hydroxy-4-oxoheptanoate, HO-CH2-CH2-CH2-CO-CH2-CH2-COOCH3, is treated with a large excess of CH3MgBr in dry ether, followed by H3O+. Count the moles of... JEE Advanced level
• Propene is treated with HBr in the presence of peroxide to give X. X is converted to its Grignard reagent with Mg in dry ether, which is treated with ethanal an... JEE Advanced level
• A compound X, C4H8O, is reduced by LiAlH4 (then H3O+) to Y. Y gives a yellow precipitate with I2/NaOH and gives turbidity with the Lucas reagent only after abou... JEE Advanced level
• Methyl benzoate is treated with excess CH3MgBr, then H3O+, and the isolated alcohol is heated with conc. H2SO4. The final organic product is JEE Advanced level
• Which of the following sequences give 2-methylpropan-2-ol, (CH3)3C-OH, as the product (after work-up)? JEE Advanced level
• An alkene C5H10 gives 2-methylbutan-1-ol on hydroboration-oxidation (BH3/THF, then H2O2/NaOH), but gives 2-methylbutan-2-ol on acid-catalysed hydration. The alk... JEE Advanced level
• 1-Methylcyclopentene is subjected to hydroboration with BH3/THF followed by H2O2/NaOH. Which statements are correct? JEE Advanced level