Chapter 22, Problem 22.56AP

Interpretation Introduction

(a)

Interpretation:

The principal organic product expected when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${}^{-}\text{CN}$ in ethanol, then ${\text{H}}_{\text{2}}\text{O}/{\text{H}}_{\text{3}}{\text{O}}^{+}$, heat is to be stated.

Concept introduction:

The $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds undergo a variety of addition reactions. The addition occurs either at the unsaturated part, at carbonyl group or at the position that involves both the parts. Such type of addition reaction of $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds that involves conjugated addition is known as Michael addition.

Answer to Problem 22.56AP

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${}^{-}\text{CN}$ in ethanol, then ${\text{H}}_{\text{2}}\text{O}/{\text{H}}_{\text{3}}{\text{O}}^{+}$, heat is shown below.

Explanation of Solution

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${}^{-}\text{CN}$ in ethanol, then ${\text{H}}_{\text{2}}\text{O}/{\text{H}}_{\text{3}}{\text{O}}^{+}$, heat is shown below.

Figure 1

In this reaction, the addition of $\text{HCN}$ occurs only on the carbon-carbon doublebond in the first step. In the second step of the reaction, the hydrolysis of cyanide group ans ester group which is already present occurs. The hydrolysis of the cyanide and ester groups give two carboxylic acid groups. The resultant product is dicarboxylic acid.

Conclusion

The principal organic product expected when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${}^{-}\text{CN}$ in ethanol, then ${\text{H}}_{\text{2}}\text{O}/{\text{H}}_{\text{3}}{\text{O}}^{+}$, heat is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation:

The principal organic product expected when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{Me}}_{\text{2}}\text{NH}$, at room temperature is to be stated.

Concept introduction:

The $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds undergo a variety of addition reactions. The addition occurs either at the unsaturated part, at carbonyl group or at the position that involves both the parts. Such type of addition reaction of $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds that involves conjugated addition is known as Michael addition.

Answer to Problem 22.56AP

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{Me}}_{\text{2}}\text{NH}$ at room temperature is shown below.

Explanation of Solution

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{Me}}_{\text{2}}\text{NH}$ at room temperature is shown below.

Figure 2

In this reaction, the addition of ${\text{Me}}_{\text{2}}\text{NH}$ occurs only on the carbon-carbon double bond. This reaction is a more or less simple addition to the double bond. This reaction is a conjugate addition of ${\text{Me}}_{\text{2}}\text{NH}$, that is, Micheal addition but the end product obtained looks like as if it is the result of addition of ${\text{Me}}_{\text{2}}\text{NH}$ on the double bond.

Conclusion

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{Me}}_{\text{2}}\text{NH}$, room temperature is shown in Figure 2.

Interpretation Introduction

(c)

Interpretation:

The principal organic product expected when $\text{ethyl}trans\text{-2-butenoate}$ reacts with $\text{NaOH}$, ${\text{H}}_{\text{2}}\text{O}$ in presence of heat is to be stated.

Concept introduction:

The $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds undergo a variety of addition reactions. The addition occurs either at the unsaturated part, at carbonyl group or at the position that involves both the parts. Such type of addition reaction of $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds that involves conjugated addition is known as Michael addition.

Answer to Problem 22.56AP

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with $\text{NaOH}$, ${\text{H}}_{\text{2}}\text{O}$ in presence of heat is shown below.

Explanation of Solution

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with $\text{NaOH}$, ${\text{H}}_{\text{2}}\text{O}$ in presence of heat is shown below.

Figure 3

The $\alpha ,\beta \text{-}$ unsaturated ester, $\text{ethyl}trans\text{-2-butenoate}$ undergoes the saponification reaction with $\text{NaOH}$ to give the sodium salt of the compound and ethanol. The salt then undergoes hydrolysis with the ${\text{H}}_{\text{2}}\text{O}$ in presence of heat and gives $\alpha ,\beta \text{-}$ unsaturated acid as the end product.

Conclusion

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with $\text{NaOH}$, ${\text{H}}_{\text{2}}\text{O}$ in presence of heat is shown in Figure 3.

Interpretation Introduction

(d)

Interpretation:

The principal organic product expected when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{CH}}_3\text{Li}$ (excess), then ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is to be stated.

Concept introduction:

The $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds undergo a variety of addition reactions. The addition occurs either at the unsaturated part, at carbonyl group or at the position that involves both the parts. Such type of addition reaction of $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds that involves conjugated addition is known as Michael addition.

Answer to Problem 22.56AP

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{CH}}_3\text{Li}$ (excess), then ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is shown below.

Explanation of Solution

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{CH}}_3\text{Li}$ (excess), then ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is shown below.

Figure 4

In this reaction, ${\text{CH}}_3\text{Li}$ attacks on the carbonyl carbon to first produce a ketone. It then attacks the ketone to give the lithium salt of $\alpha ,\beta \text{-}$ unsaturated tertiary alcohol which on acidic workup gives the $\alpha ,\beta \text{-}$ unsaturated tertiary alcohol.

Conclusion

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{CH}}_3\text{Li}$ (excess), then ${\text{H}}_{\text{3}}{\text{O}}^{+}$ is shown in Figure 4.

Interpretation Introduction

(e)

Interpretation:

The principal organic product expected when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{H}}_{\text{2}}$, catalyst is to be stated.

Concept introduction:

The $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds undergo a variety of addition reactions. The addition occurs either at the unsaturated part, at carbonyl group or at the position that involves both the parts. Such type of addition reaction of $\alpha ,\beta \text{-}$ unsaturated carbonyl compounds that involves conjugated addition is known as Michael addition.

Answer to Problem 22.56AP

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{H}}_{\text{2}}$, catalyst is shown below.

Explanation of Solution

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{H}}_{\text{2}}$, catalyst is shown below.

Figure 5

In this reaction, the addition of ${\text{H}}_{\text{2}}$ occurs only on the carbon-carbon double bond. This reaction is a more or less simple addition to the double bond. This reaction isthe selective reduction of the double bond in the presence of the carbonyl group.

Conclusion

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with ${\text{H}}_{\text{2}}$, catalyst is shown in Figure 5.

Interpretation Introduction

(f)

Interpretation:

The principal organic product expected when $\text{ethyl}trans\text{-2-butenoate}$ reacts with $\text{1, 3-cyclopentadiene}$ is to be stated.

Concept introduction:

Diels-Alder reaction is a cycloaddition reaction. The reaction is known as a $\left[4+2\right]$ cycloaddition reaction in which a cis-diene and a dienophile react with each other in the presence of heat and give a six-membered ring.

Answer to Problem 22.56AP

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with $\text{1, 3-cyclopentadiene}$ is shown below.

Explanation of Solution

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with $\text{1, 3-cyclopentadiene}$ is shown below.

Figure 6

The reaction of $\text{ethyl}trans\text{-2-butenoate}$ with $\text{1, 3-cyclopentadiene}$ is Diels Alder reaction. The $\left[4+2\right]$ cycloaddition of diene $\text{1, 3-cyclopentadiene}$ and dienophile $\text{ethyl}trans\text{-2-butenoate}$ takes place. The double bond present in the $\text{ethyl}trans\text{-2-butenoate}$ undergoes the addition reaction with $\text{1, 3-cyclopentadiene}$ to give a six-membered ring product.

Conclusion

The principal organic product obtained when $\text{ethyl}trans\text{-2-butenoate}$ reacts with $\text{1, 3-cyclopentadiene}$ is shown in Figure 6.