Answer :
Final answer:
The statement in the question is false; esters and compounds with leaving groups such as Cl react with two equivalents of Grignard reagent to form a tertiary alcohol with two identical alkyl groups derived from the Grignard reagent.
Explanation:
The statement that only one carbon group with a Grignard reagent is needed because the reaction occurs twice to kick out the OEt group or the Cl group is false.
Grignard reagents react with carbonyl containing compounds through nucleophilic addition forming a C-C bond. With esters, the first reaction replaces the OR' group with the alkyl group of the Grignard, giving a ketone.
This ketone is then attacked by a second molecule of Grignard reagent leading to the formation of a tertiary alcohol upon neutralization with H3O+.
The overall process involves two additions of the Grignard reagent to the ester or a compound with a leaving group like Cl. After the first addition, the intermediate is not stable due to the reforming of the carbonyl group.
Thus, a second addition occurs resulting in the formation of a 3° alcohol with two of the same alkyl groups, both derive from the Grignard reagent.
Additionally, reacting Grignard reagents with ethylene oxide produces a primary alcohol with a two-carbon extension from the original Grignard reagent. Therefore, the process and outcome depend on the nature of the reactant and the Grignard reagent.
