Question

Which of the following is a Wolf - Kishner reduction?

Options

• \[\ce{- C ≡ N + 2[H] ->[SnCl2][dil HCl] - CH = NH*HCl ->[H3O+] - CHO + NH4Cl}\]

• \[\ce{- COCl ->[H2][Pd-BaSO4] - CHO + HCl}\]

• \[\ce{- Co - + 4[H] ->[Zn-Hg/conc. HCl][\Delta] - CH2 - + H2O}\]

• \[\begin{array}{cc}
  \backslash\phantom{................}\backslash\phantom{............................}\backslash\phantom{..........}\\
  \ce{C = O ->[H2N-NH2][-H2O] C = N-NH2 ->[KOH/ethylene glycol][\Delta] CH2 + N2}\\
  /\phantom{................}/\phantom{............................}/\phantom{..........}\end{array}\]

Answer 1

\[\begin{array}{cc}
\backslash\phantom{................}\backslash\phantom{............................}\backslash\phantom{..........}\\
\ce{C = O ->[H2N-NH2][-H2O] C = N-NH2 ->[KOH/ethylene glycol][\Delta] CH2 + N2}\\
/\phantom{................}/\phantom{............................}/\phantom{..........}\end{array}\]

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.

\[\begin{array}{cc}
\backslash\phantom{................}\backslash\phantom{............................}\backslash\phantom{..........}\\
\ce{C = O ->[H2N-NH2][-H2O] C = N-NH2 ->[KOH/ethylene glycol][\Delta] CH2 + N2}\\
/\phantom{................}/\phantom{............................}/\phantom{..........}\end{array}\]