Question

Give the structure of the major product expected from the following reaction:

Reaction of propanal with methyl magnesium bromide followed by hydrolysis.

Answer 1

The nucleophile \[\ce{MgBr}\] attacks the carbonyl carbon of propanal to form the final product, followed by hydrolysis to form the secondary alcohol.

\[\begin{array}{cc}
\ce{CH3 - CH2 - C = O + ^{\delta-}CH3^{\delta+}MgBr -> CH3 - CH2 - C - CH3 ->[H3O+] CH3 - CH2 - C - CH3}\\
\phantom{............}|\phantom{..........................................}|\phantom{.............................}|\phantom{.....}\\
\phantom{.........}\ce{H}\phantom{.........................................}\ce{O^-MgBr}\phantom{.....................}\ce{OH}\\
\end{array}\]