What type of products do you expect when Grignard reagents react with esters?

When Grignard reagents react with esters, the primary outcome is the formation of alcohols. Grignard reagents, which are organomagnesium compounds, are highly nucleophilic and can attack the carbonyl carbon of the ester.

The reaction can be understood through the following steps:

1. The nucleophilic carbon from the Grignard reagent attacks the electrophilic carbonyl carbon of the ester, leading to the formation of a tetrahedral intermediate.

2. This intermediate is then protonated, typically by the addition of water or another proton source, resulting in the formation of a tertiary alcohol if the ester is a simple one.

In the case of esters specifically, the reaction not only produces an alcohol but also requires that the ester is converted into a ketone intermediate before the final alcohol product is formed upon treatment with another equivalent of the Grignard reagent. This showcases that the Grignard reagent effectively adds twice to the ester.

By understanding this mechanism, it becomes clear why the reaction predominantly yields alcohols, distinguishing it from other functional group transformations involving similar reagents or substrates.