Chapter 19, Problem 19.45P

Interpretation Introduction

(a)

Interpretation:

The given transformation is to be carried out identifying the appropriate reagent.

Concept introduction:

The carbonyl groups of aldehyde or ketone can be reduced to methylene, i.e., $\text{C=O}$ to ${\text{CH}}_{\text{2}}$, using the reactions like Wolff-Kishner reduction, Clemmensen, and Raney-nickel. If a carbonyl compound has acid sensitive other functional groups or the functional groups that are susceptible to reaction with nucleophilic thiols ($\text{RSH}$) or with ${\text{H}}_{\text{2}}$ in the presence of a metal catalyst, then the Woff-Kishner reduction is preferable. The reagent used for Wolff-Kishner reduction is ${\text{NH}}_{\text{2}}{\text{NH}}_{\text{2}}\text{, KOH/}\Delta$.

Interpretation Introduction

(b)

Interpretation:

The given transformation is to be carried out identifying the appropriate reagent.

Concept introduction:

The carbonyl groups of aldehyde or ketone can be reduced to methylene, i.e., $\text{C=O}$ to ${\text{CH}}_{\text{2}}$, using the reactions like Wolff-Kishner reduction, Clemmensen, and Raney-nickel.

If a carbonyl compound has base sensitive other functional groups or the functional groups that are susceptible to reaction with nucleophilic thiols ($\text{RSH}$) or with ${\text{H}}_{\text{2}}$ in the presence of a metal catalyst, then the Clemmensen reduction is preferable. The reagent used for Clemmensen reduction is $\text{Zn/Hg, HCl}$.

Interpretation Introduction

(c)

Interpretation:

The given transformation is to be carried out identifying the appropriate reagent.

Concept introduction:

The carbonyl groups of aldehyde or ketone can be reduced to methylene, i.e., $\text{C=O}$ to ${\text{CH}}_{\text{2}}$, using the reactions like Wolff-Kishner reduction, Clemmensen, and Raney-nickel. If a carbonyl compound has acid sensitive other functional groups or the functional groups that are susceptible to reaction with nucleophilic thiols ($\text{RSH}$) or with ${\text{H}}_{\text{2}}$ in the presence of a metal catalyst, then the Woff-Kishner reduction is preferable. The reagent used for Wolff-Kishner reduction is ${\text{NH}}_{\text{2}}{\text{NH}}_{\text{2}}\text{, KOH/}\Delta$.