Question

The reaction sequence $C{H}_{3}C{H}_{2}COOH\stackrel{SOC{l}_2}{\to }A\stackrel{Pd/BaS{O}_4}{\to }B\stackrel{HOC{H}_{2}C{H}_{2}OH}{\to }C$
${}^{\prime }C$ ' is most likely to be

• A.
• B.
• C. $C{H}_3-C{H}_2-CHO$
• D.

Answer 1

Answer: (B)

When propionic acid reacts with thionyl chloride $\left(SOC{l}_2\right)$, then - $OH$ group of carboxylic acid replaced by $-Cl$ group and propanoyl chloride $(A)$ is formed which reacts with $Pd/BaS{O}_4$ and compound $(B)$, ie, propanal is obtained (Rosenmund reaction). This compound $(B)$, ie, propanal reacts with ethylene glycol, gives a cyclic acetal compound