Chapter 18, Problem 18.20P

(a)

Interpretation Introduction

Interpretation:

Product formed when ethyl benzoate reacts with the given reagent has to be drawn.

Concept Introduction:

Ester Hydrolysis: Ester hydrolysis can be caused by acid and base.

Saponification: Ester hydrolysis taking place in presence of base such as $NaOH$ or $KOH$ is known as saponification. Ester reacts with hydroxide ion forming carboxylic acid which again reacts with base resulting in the formation of a caboxylate anion.

Acid-catalyzed hydrolysis: In presence of strong acid such as ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$, ester reacts with water to form the corresponding alcohol and carboxylic acid. It is the reverse of esterification.

Explanation of Solution

The synthesis of product transformation is shown below.

The ethyl benzoate (A) is reacted with sodium hydroxide in presence of basic conditions which corresponding yields the product (B). In this reaction addition and elimination process was occurred.

(b)

Interpretation Introduction

Interpretation:

Product formed when ethyl benzoate reacts with the given reagent has to be drawn.

Concept Introduction:

Ester Hydrolysis: Ester hydrolysis can be caused by acid and base.

Saponification: Ester hydrolysis taking place in presence of base such as $NaOH$ or $KOH$ is known as saponification. Ester reacts with hydroxide ion forming carboxylic acid which again reacts with base resulting in the formation of a caboxylate anion.

Acid-catalyzed hydrolysis: In presence of strong acid such as ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$, ester reacts with water to form the corresponding alcohol and carboxylic acid. It is the reverse of esterification.

Explanation of Solution

The synthesis of product transformation is shown below.

The ethyl benzoate (A) is undergoes for simple acid catalyzed hydrolysis, followed by heating to give a target compound (B), which is a benzoic acid. 

(c)

Interpretation Introduction

Interpretation:

Product formed when ethyl benzoate reacts with the given reagent has to be drawn.

Concept Introduction:

Amide: One $-N{H}_2$, $-NHR\text{'}$ or $-NR{\text{'}}_2$ group is attached to the carbonyl carbon atom of the compound. It is represented as $RCONR{\text{'}}_2$.

Amide Formation: Amide is formed when a carboxylic acid reacts with an amine or ammonia.

• Primary amide is produce when a carboxylic acid reacts with ammonia.
• Secondary and tertiary amide is produce when a carboxylic acid reacts with primary and secondary amine respectively.

Explanation of Solution

The synthesis of product transformation is shown below.

The ethyl benzoate (A) is reacted with n-butylamine in presence of basic conditions which corresponding yields the product (B).

(d)

Interpretation Introduction

Interpretation:

Product formed when ethyl benzoate reacts with the given reagent has to be drawn.

Concept Introduction:

Diisobutylaluminium hydride (DIBALH): It is prepared by refluxing triisobutylaluminium in the solvent heptane.

DIBAL-H: is a strong reducing reagent most functional group.

DIBAL-H is a selective reagent (like, alkyne to alkene, ester or ketone to aldehyde), moreover it is a special reductant of nitrile to aldehyde. 

Explanation of Solution

The synthesis of product transformation is shown below.

The equal amount of ethyl benzoate (A) is reacted with Diisobutylaluminium hydride (DIBALH) under dry ice conditions at $-{78}^{o}C$ followed by simple water work up method which corresponding yields the benzaldehyde (B). In this reaction addition and elimination process was occurred.

(e)

Interpretation Introduction

Interpretation:

Product formed when ethyl benzoate reacts with the given reagent has to be drawn.

Concept Introduction:

Reduction: Aldehydes or ketones undergoing reduction by using reducing agent like $\text{LAH}$ or ${\text{NaBH}}_{\text{4}}$ which provides alcohol.

LAH Reduction: The saturated/unsaturated aldehyde and ketones in the presence of sodium metal in LAH and carbonyl compound produced saturated alcohols. The keto group involves in the reduction process of LAH, this end up reducing to give the alcohols.

Explanation of Solution

The synthesis of product transformation is shown below.

The ethyl benzoate (A) undergoes for LAH reduction process followed by simple hydrolysis workup method to give a target product (B). The obtained product namely benzyl alcohol. 

(f)

Interpretation Introduction

Interpretation:

Product formed when ethyl benzoate reacts with the given reagent has to be drawn.

Concept Introduction:

Alkyl or aryl magnesium halides ($RMgX$) are known as Grignard reagent. The Grignard reaction is an organometallic chemical reaction in which the Grignard reagent act as nucleophile and attack electrophilic carbon atom that are present within polar bonds to yield a carbon-carbon bond.

Synthesis of Grignard reagent is shown below,

  $\underset{Alkyl/arylhalide}{R-X}+Mg\stackrel{Ether}{\to }\underset{Grignardreagent}{RMgX}$

Acid Catalyzed Hydration Reaction: The reaction involves breaking of $\text{π}$-bonds between carbon-carbon multiple bonds and addition of alcohol to more substituted position of carbon in the molecule.

Explanation of Solution

The synthesis of product transformation is shown below.

Two equivalents of Grignard reagent (A) is reacted with hydrogen chloride and fallowed by hydrolysis workup method, which corresponding yields the triphenyl methanol (B) it is a target molecule.