Answer :
Final answer:
The correct combination of ester and bromo-Grignard reagent to prepare a tertiary alcohol is option (d) butyl ester with isopropyl bromo-Grignard reagent. This takes advantage of the reactivity of Grignard reagents with esters to form tertiary alcohols.
Explanation:
To prepare a tertiary alcohol using an ester and a bromo-Grignard reagent, we need to select starting materials such that upon reaction, we will introduce a third alkyl group to a secondary carbon atom with an existing hydroxyl (OH) group. Looking at the options provided, the correct combination would be (d) butyl ester, isopropyl bromo-Grignard reagent. The butyl ester will provide the initial carbonyl carbon with two alkyl groups, and the isopropyl bromo-Grignard reagent will add the third alkyl group to form the tertiary alcohol upon reaction with the ester.
The reaction takes place through a nucleophilic attack by the Grignard reagent on the carbonyl carbon of the ester, followed by a series of steps that lead to the formation of the tertiary alcohol. This is consistent with the synthesis of alcohols using Grignard reagents and esters.
