Question

Identify substrate ‘A’ in the following conversion:

\[\ce{A \underset{dry ether}{\overset{CH3MgCl}{->}} complex \overset{H3O+}{->} acetone}\]

Options

• CH₃CHО

• CH₃CN

• HCN

• CH₃COCI

Answer 1

CH₃CN

Explanation:

Ketones are prepared by reacting nitriles with Grignard reagent in dry ether as a solvent, followed by acid hydrolysis.

\[\ce{H3C - C ≡ N + H3CMgCl}\]
(Ethanenitrile)

\[\begin{array}{cc}
\ce{CH3 - C = NMgCl \overset{H3O+}{->} \underset{(Acetone)}{CH3 - CO - CH3} + NH3 + Mg(Cl)OH}\\
|\phantom{..........................................................................}\\
\ce{H3C}\phantom{...............................................................................}
\end{array}\]