The product formed in the first step of the reaction of
Question:

The product formed in the first step of the reaction of

with excess $\mathrm{Mg} / \mathrm{Et}_{2} \mathrm{O}\left(\mathrm{Et}=\mathrm{C}_{2} \mathrm{H}_{5}\right)$ is :

Correct Option: , 3

Solution: