Question

Predict the major products of the following reactions:

(a) (b)

(c) (d)

Short answer

(a) The major product of the reaction is shown below.

(b) The major product of the reaction is shown below.

(c) The major product of the reaction is shown below.

(d) The major product of the reaction is shown below.

Step-by-step solution

Wolf-Kishner Reduction

InWolf Kishner reduction, aldehydes and ketones react with hydrazine$\left({\mathrm{H}}_2\mathrm{N}-{\mathrm{NH}}_2\right)$to form hydrazone. The so formed hydrazone is then heated with a strong base like potassium hydroxide $\left(\mathrm{KOH}\right)$ at the temperature range of $\left(140‐200°\mathrm{C}\right)$to form hydrocarbon.

In Clemmensen reduction, aldehyde and ketones are reduced to hydrocarbons in the presence of zinc amalgam $\left(\mathrm{Zn}-\mathrm{Hg}\right)$ and concentrated hydrochloric acid $\left(\mathrm{HCl}\right)$.

Major product of the reaction

(a) Acidic solution of zinc dissolved in mercury as a reducing agent is used to reduce carbonyl group of ketone to a methylene group. The corresponding reaction is shown below.

Major Product of The Reaction

(b) Hydrazine under basic condition reduces carbonyl group of ketone to a methylene group. The corresponding reaction is shown below.

Major Product of The Reaction

(c) Hydrazine under basic condition reduces carbonyl group of ketone to a methylene group. The corresponding reaction is shown below.

Major Product of The Reaction

(d) Due to acidic conditions, the acetal will hydrolyze first and then both ketones will be reduced to methylene groups. The corresponding reaction is shown below.

Major Product of The Reaction