Exams › JEE Main › Chemistry

Which alkyl halide is required to prepare 5-methyl-2-hexanone from acetoacetic ester?

1. (CH3)2CHBr
2. (CH3)2CHCH2Br
3. CH3CH2CHBrCH3
4. (CH3)2CHCH2CH2Br

Correct answer: (CH3)2CHCH2Br

Solution

Acetoacetic ester after alkylation, hydrolysis and decarboxylation gives a methyl ketone CH3-CO-CH2-R. For 5-methyl-2-hexanone, CH3-CO-CH2-CH2-CH(CH3)-CH3, the fragment R is -CH2-CH(CH3)2 (isobutyl), so the required alkyl halide is isobutyl bromide, (CH3)2CHCH2Br.

Related JEE Main Chemistry questions

• Lactic acid loses its optical activity when the hydroxyl group is replaced by hydrogen because
• Which is the most suitable technique for separating a mixture of sugars?
• Which statement correctly compares the staggered and eclipsed conformations of ethane?
• Which statement correctly describes a common feature shared by optical and geometrical isomerism?
• Which substituent lowers the reactivity of a benzene ring toward electrophilic substitution, yet still mainly directs a new group to the ortho and para positions?
• Among the following substances, which has the greatest affinity for a proton?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →