Question

How will you bring about the following conversion?

Bromomethane to propanone

How will you bring about the following conversion in not more than two steps?

Bromomethane to propanone

Answer 1

\[\begin{array}{cc}
\ce{\underset{Bromomethane}{CH3 - Br} ->[Alc. KCN][C2H5OH, -H2O, \Delta] \underset{Acetonitrile}{CH3CN} ->[CH3MgBr/ether] [CH3 - C = NMgBr] ->[H^+/H2O][-NH3, -Mg(OH)Br] CH3 - C = O}\\
\phantom{.....................................................}|\phantom{....................................}|\phantom{.}\\
\phantom{..........................................................}\ce{CH3}\phantom{...............................}\ce{\underset{propanone}{CH3}}\phantom{..}
\end{array}\]

Answer 2

\[\begin{array}{cc}
\ce{\underset{Bromomethane}{CH3 - Br} ->[HC = C- Na+][Liq{.} NH3, -NaBr] \underset{Propyne}{CH3 - C ≡ CH} ->[Dil{.} H2SO4][HgSO4] CH3 - C - CH3}\\
\phantom{....................................................}||\phantom{.}\\
\phantom{.....................................................}\ce{\underset{propanone}{O}}\phantom{..}
\end{array}\]