Question

Which of the following is a Wolf - Kishner reduction?

विकल्प

• $$-\mathrm{C}\equiv \mathrm{N}+2[\mathrm{H}]\underset{\mathrm{dil}\mathrm{HCl}}{\overset{\mathrm{SnCl}{\phantom{A}}_2}{\to }}-\mathrm{CH}=\mathrm{NH}\cdot \mathrm{HCl}\stackrel{\mathrm{H}{\phantom{A}}_3\mathrm{O}{\phantom{A}}^{+}}{\to }-\mathrm{CHO}+\mathrm{NH}{\phantom{A}}_4\mathrm{Cl}$$

• $$-\mathrm{COCl}\underset{\mathrm{Pd}-\mathrm{BaSO}{\phantom{A}}_4}{\overset{\mathrm{H}{\phantom{A}}_2}{\to }}-\mathrm{CHO}+\mathrm{HCl}$$

• $$-\mathrm{Co}-+4[\mathrm{H}]\underset{\mathrm{\Delta }}{\overset{\mathrm{Zn}-\mathrm{Hg}/\mathrm{conc}\cdot \mathrm{HCl}}{\to }}-\mathrm{CH}{\phantom{A}}_2-+\mathrm{H}{\phantom{A}}_2\mathrm{O}$$

• $$\begin{array}{c}\mathrm{\setminus }\phantom{................}\mathrm{\setminus }\phantom{............................}\mathrm{\setminus }\phantom{..........}\\ \mathrm{C}=\mathrm{O}\underset{-\mathrm{H}{\phantom{A}}_2\mathrm{O}}{\overset{\mathrm{H}{\phantom{A}}_2\mathrm{N}-\mathrm{NH}{\phantom{A}}_2}{\to }}\mathrm{C}=\mathrm{N}-\mathrm{NH}{\phantom{A}}_2\underset{\mathrm{\Delta }}{\overset{\mathrm{KOH}/\mathrm{ethylene}\mathrm{glycol}}{\to }}\mathrm{CH}{\phantom{A}}_2+\mathrm{N}{\phantom{A}}_2\\ /\phantom{................}/\phantom{............................}/\phantom{..........}\end{array}$$

Answer 1

$$\begin{array}{c}\mathrm{\setminus }\phantom{................}\mathrm{\setminus }\phantom{............................}\mathrm{\setminus }\phantom{..........}\\ \mathrm{C}=\mathrm{O}\underset{-\mathrm{H}{\phantom{A}}_2\mathrm{O}}{\overset{\mathrm{H}{\phantom{A}}_2\mathrm{N}-\mathrm{NH}{\phantom{A}}_2}{\to }}\mathrm{C}=\mathrm{N}-\mathrm{NH}{\phantom{A}}_2\underset{\mathrm{\Delta }}{\overset{\mathrm{KOH}/\mathrm{ethylene}\mathrm{glycol}}{\to }}\mathrm{CH}{\phantom{A}}_2+\mathrm{N}{\phantom{A}}_2\\ /\phantom{................}/\phantom{............................}/\phantom{..........}\end{array}$$

Explanation:

In the presence of NH₂NH₂, the carbonyl group is changed to the equivalent alkane group, which is then followed by KOH and ethylene glycol.

$$\begin{array}{c}\mathrm{\setminus }\phantom{................}\mathrm{\setminus }\phantom{............................}\mathrm{\setminus }\phantom{..........}\\ \mathrm{C}=\mathrm{O}\underset{-\mathrm{H}{\phantom{A}}_2\mathrm{O}}{\overset{\mathrm{H}{\phantom{A}}_2\mathrm{N}-\mathrm{NH}{\phantom{A}}_2}{\to }}\mathrm{C}=\mathrm{N}-\mathrm{NH}{\phantom{A}}_2\underset{\mathrm{\Delta }}{\overset{\mathrm{KOH}/\mathrm{ethylene}\mathrm{glycol}}{\to }}\mathrm{CH}{\phantom{A}}_2+\mathrm{N}{\phantom{A}}_2\\ /\phantom{................}/\phantom{............................}/\phantom{..........}\end{array}$$