(N/A) The Wolff-Kishner reduction is a chemical reaction used to reduce the carbonyl group of aldehydes and ketones to a $CH_{2}$ group.
Mechanism and Reaction:
$1$. The aldehyde or ketone is first treated with hydrazine $(NH_{2}NH_{2})$ to form a hydrazone intermediate,with the loss of a water molecule $(H_{2}O)$.
$2$. The hydrazone is then heated (at $453-473 \ K$) with a strong base like potassium hydroxide $(KOH)$ in a high-boiling solvent such as ethylene glycol.
$3$. This process results in the evolution of nitrogen gas $(N_{2})$ and the formation of the corresponding hydrocarbon.
General Reaction:
$>C=O + NH_{2}-NH_{2}$ $\xrightarrow{-H_{2}O} >C=N-NH_{2}$ $\xrightarrow{KOH, \Delta, \text{ethylene glycol}} >CH_{2} + N_{2}$
Example $1$: Reduction of acetaldehyde to ethane
$CH_{3}CHO + NH_{2}NH_{2}$ $\rightarrow CH_{3}CH=NNH_{2}$ $\xrightarrow{KOH, \text{glycol}, \Delta} CH_{3}CH_{3} + N_{2}$
Example $2$: Reduction of acetone to propane
$(CH_{3})_{2}CO + NH_{2}NH_{2}$ $\rightarrow (CH_{3})_{2}C=NNH_{2}$ $\xrightarrow{KOH, \text{glycol}, \Delta} CH_{3}CH_{2}CH_{3} + N_{2}$