Final answer:
Upon reaction with two equivalents of organometallic reagents, esters and acid chlorides typically yield tertiary alcohols after work-up due to the sequential addition of the organometallic compound to the carbonyl group.
Step-by-step explanation:
When esters or acid chlorides react with two equivalents of organometallic reagents, the product formed is generally a tertiary alcohol. Organometallic reagents, such as Grignard reagents or organolithium compounds, react with esters in two steps.
In the first step, an equivalent of the organometallic reagent attacks the ester to form a ketone and an alkoxide. Then, a second equivalent of the organometallic reagent adds to this newly formed ketone to yield a tertiary alcohol following acid work-up.