Question

$\mathrm{CH}{}_3\mathrm{CHO}+\mathrm{HCHO}\underset{\text{Heat}}{\overset{\mathrm{Dil}\cdot \mathrm{NaOH}}{\to }}\mathrm{A}$
$\underset{\mathrm{H}{}_3\mathrm{O}{}^{+}}{\overset{\mathrm{HCN}}{\to }}\mathrm{B}$
The structure of the compound $B$ is

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

$C{H}_{3}CHO+HCHO\underset{\text{cross aldol condensethem}}{\overset{\text{dil.NaOH}}{\to }}$

$\underset{\text{3-hydroxy propanal}}{HOC{H}_2-C{H}_2-CHO}$

$\underset{\text{-}{\mathrm{H}}_2\mathrm{O}}{\overset{\text{Heat}}{\to }}\underset{\text{prop-2-enal (A)}}{C{H}_2=CH-CHO}$

$\underset{\text{1, 2, addition}}{\overset{\text{HCN}}{\to }}$