Benzoic acid on reaction with ${\mathrm{SOCl}}_2$ gives (A). (A) on reduction with $\mathrm{Pd}-{\mathrm{BaSO}}_4$, ${\mathrm{H}}_2$ in presence of quinoline affords (B). (B) reacts with ${\mathrm{NH}}_2\mathrm{OH}, \mathrm{HCl}$ in presence of ${\mathrm{CH}}_3\mathrm{COONa}$ in aqueous ethanol to furnish (C). (C) on reaction with ${\mathrm{PCl}}_5$ gives (D). Write the structures of (A), (B), (C) and (D). What is the role of ${\mathrm{CH}}_3\mathrm{COONa}$ in the conversion of (B) to (C)?

Identify A, B, C and D in the following steps of the reaction of acetaldehyde with dilute aqueous solution of $\mathrm{NaOH}$:

${\mathrm{CH}}_3\mathrm{CHO}+\stackrel{-}{\mathrm{O}}\mathrm{H}\rightleftharpoons \mathrm{A}+\mathrm{B}$

${\mathrm{CH}}_3\mathrm{CHO}+\mathrm{A}\rightleftharpoons \mathrm{C}$

$\mathrm{C}+\mathrm{B}\rightleftharpoons \mathrm{D}+\stackrel{-}{\mathrm{O}}\mathrm{H}$

Write the structures of $\mathrm{A}$ to $\mathrm{D}$ in the following reactions:

$\mathrm{RCOR}\text{'}\stackrel{{\mathrm{NH}}_2{\mathrm{NH}}_2}{\to }\mathrm{A}\underset{\mathrm{ethylene} \mathrm{glycol}, {180}^{\mathrm{o}}\mathrm{C}}{\overset{{\mathrm{C}}_2{\mathrm{H}}_5\stackrel{-}{\mathrm{O}}\stackrel{+}{\mathrm{Na}}}{\to }}\mathrm{B}$

${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CO}}_2\mathrm{Ag}\underset{{\mathrm{CCl}}_4}{\overset{{\mathrm{Br}}_2}{\to }}\mathrm{C}$

${\mathrm{CH}}_3\mathrm{CHO}+{\mathrm{NaHSO}}_3\to \mathrm{D}$

Convert the following:

(p) Benzaldehyde to Cinnamic acid.

(q) Acetic acid to acetaldehyde.

Mention the reagents used for the following conversions:

(m) ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_3\stackrel{\mathrm{A}}{\to }{\mathrm{C}}_6{\mathrm{H}}_5\mathrm{CHO}$

(n) ${\mathrm{CH}}_3\mathrm{CHO}\stackrel{\mathrm{B}}{\to }{\mathrm{CH}}_3{\mathrm{COOC}}_2{\mathrm{H}}_5$

(o) ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{CHO}\stackrel{\mathrm{C}}{\to }{\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COCH}\left(\mathrm{OH}\right){\mathrm{C}}_6{\mathrm{H}}_5$

(p) ${\mathrm{CH}}_3{\mathrm{COCH}}_3\stackrel{\mathrm{D}}{\to }{\left({\mathrm{CH}}_3\right)}_2\mathrm{C}\left(\mathrm{OH}\right){\mathrm{CH}}_2{\mathrm{COCH}}_3$

(q) ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}\stackrel{\mathrm{E}}{\to }{\mathrm{CH}}_3\mathrm{CH}\left(\mathrm{Br}\right)\mathrm{COOH}$

(r) ${\mathrm{CH}}_3{\mathrm{COCH}}_3\stackrel{\mathrm{F}}{\to }{\mathrm{CH}}_3{\mathrm{COCH}}_2\mathrm{Br}$

An organic compound produces acetic acid and ethanol on acid hydrolysis. Write the structural formula of the compound. How can you prepare the compound from acetaldehyde in one step?