Which of the following sequences give 2-methylpropan-2-ol, (CH3)3C-OH, as the product (after work-up)?

Propanone with CH3MgBr, then H3O+

Methyl ethanoate with excess CH3MgBr, then H3O+

2-Methylpropene with dilute H2SO4 and water

Propanone with CH3MgBr, then H3O+

Methyl ethanoate with excess CH3MgBr, then H3O+

2-Methylpropene with dilute H2SO4 and water

2-Methylpropene with BH3 in THF, then H2O2/NaOH

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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3ap182

Which of the following sequences give 2-methylpropan-2-ol, $(CH X_{3}) X_{3} C - OH$ , as the product (after work-up)?

APropanone with $CH X_{3} MgBr$ , then $H X_{3} O X^{+}$
BMethyl ethanoate with excess $CH X_{3} MgBr$ , then $H X_{3} O X^{+}$
C2-Methylpropene with dilute $H X_{2} SO X_{4}$ and water
D2-Methylpropene with $BH X_{3}$ in THF, then $H X_{2} O X_{2}$ / $NaOH$

Answer: A, B, C

Propanone plus

CH X_{3} MgBr

gives the tertiary alcohol. The ester takes two

CH X_{3} MgBr

and the acyl methyl is the third methyl group, so

(CH X_{3}) X_{3} COH

forms. Markovnikov hydration of 2-methylpropene gives the tertiary cation and the same alcohol. Hydroboration-oxidation is anti-Markovnikov and gives 2-methylpropan-1-ol.

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Which of the following sequences give 2-methylpropan-2-ol, (CHX3​)X3​C−OH, as the product (after work-up)?

Answer: A, B, C

More questions on Preparation of alcohols including from carbonyls and Grignard

Which of the following sequences give 2-methylpropan-2-ol, $(CH X_{3}) X_{3} C - OH$ , as the product (after work-up)?