The IUPAC name of the product formed by the reaction of propanone with methylmagnesium bromide followed by hydrolysis is
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 2-Methylpropan-2-ol
A Grignard reagent (RMgX) adds to the C=O group of an aldehyde or ketone. The alkyl group R attaches to the carbonyl carbon, and hydrolysis of the adduct gives an alcohol.
Propanone is a ketone, so it gives a tertiary alcohol. The methyl group of \( \ce{CH3MgBr} \) joins the carbonyl carbon, which already carries two methyl groups:
\( \displaystyle \ce{(CH3)2C=O + CH3MgBr -> (CH3)3C-OMgBr} \xrightarrow{\ce{H2O}} \ce{(CH3)3C-OH + Mg(OH)Br} \)
The product, \( \ce{(CH3)3COH} \), has a three-carbon chain with the –OH group and a methyl branch on C-2, so its IUPAC name is 2-methylpropan-2-ol (tert-butyl alcohol).
NCERT (2026-27 edition):
From Grignard Reagents
