Question

Match List-I with List-II

List-I (Chemical reaction)	List-II (Reagent used)
(a)$C{H}_{3}COOC{H}_{2}C{H}_3\to C{H}_{3}C{H}_{2}OH$	(i)$C{H}_{3}MgBr/H_3{O}^{+}$ (1 equivalent)
(b) $C{H}_{3}COOC{H}_3\to C{H}_{3}CHO$	(ii)$H_{2}S{O}_4/H_{2}O$
(c) $C{H}_{3}C\equiv N\to C{H}_{3}CHO$	(iii)$DIBAL-H/H_{2}O$
(d) $C{H}_{3}C\equiv N\to C{H}_{3}COC{H}_3$	(iv) $SnC{l}_2,HCl/H_{2}O$

Choose the most appropriate match.

<!--td {border: 1px solid #cccccc;}br {mso-data-placement:same-cell;}--> JEE MAIN 2021

• A. $\left(a\right)-\left(iv\right),\left(b\right)-\left(ii\right),\left(c\right)-\left(iii\right),\left(d\right)-\left(i\right)$
• B. $\left(a\right)-\left(ii\right),\left(b\right)-\left(iii\right),\left(c\right)-\left(iv\right),\left(d\right)-\left(i\right)$
• C. $\left(a\right)-\left(iii\right),\left(b\right)-\left(ii\right),\left(c\right)-\left(i\right),\left(d\right)-\left(iv\right)$
• D. $\left(a\right)-\left(ii\right),\left(b\right)-\left(iv\right),\left(c\right)-\left(iii\right),\left(d\right)-\left(i\right)$

Answer 1

The correct option is B $\left(a\right)-\left(ii\right),\left(b\right)-\left(iii\right),\left(c\right)-\left(iv\right),\left(d\right)-\left(i\right)$

(a) Ester get hydrolysed to respective acid and alcohol in presence of sulphuric acid.
$C{H}_{3}COOC{H}_{2}C{H}_3\underset{H_{2}O}{\overset{H_{2}S{O}_4}{\to }}C{H}_{3}COOH+C{H}_{3}C{H}_{2}OH$


(b) DIBAL-H will reduce ester group to aldehyde.
$C{H}_{3}COOC{H}_3\underset{H_{2}O}{\overset{DIBAL-H}{\to }}C{H}_3-CHO+C{H}_{3}OH$

(c)
This reaction is called stephen reaction. It involves the preparation of aldehydes from nitriles using tin(II) chloride, hydrochloric acid and quenching the resulting iminium salt with water. During the synthesis, ammonium chloride is also produced.

(d) When nitriles react with grignard reagent $R^{-}$ from the grignard will undergo nulceophilic addtion reaction to form imine product.
Imine will undergo hydrolysis to form keto product.

So, the correct match is
$\left(a\right)-\left(ii\right),\left(b\right)-\left(iii\right),\left(c\right)-\left(iv\right),\left(d\right)-\left(i\right)$

Cyanides can also be converted to aldehydes by $DIBAL-H/H_{2}O$ as well.