Chapter 27, Problem 27.50P

Draw the products of each reaction.

a. c.

b. d.

Interpretation Introduction

(a)

Interpretation: The product formed for the given reaction is to be drawn.

Concept introduction: Curved arrows aid in determining the movement and flow of electrons in the reaction. The electrons that take part in the chemical reactions are shown by the curved arrows.

In the sigmatropic rearrangement, the rearrangement of pi bond and the breaking of sigma bond take place. This results in the generation of new sigma bond in the product. In this type of rearrangement, the number of pi bonds remains constant in the reactant as well as in the product.

Answer to Problem 27.50P

The product formed for the given reaction is $\text{Cyclooct}-4-\text{enone}$ shown below.

Explanation of Solution

The given reaction is shown below.

Figure 1

The product formed for the given reaction is shown below.

Figure 2

In the given reaction, curved arrows shows the movement of pi bonds to give the final product. In this type of reaction, the compound undergoes to the $\left[3,3\right]$ sigmatropic rearrangement in which old sigma bond breaks and results in the formation of new sigma bonds to give the desired product.

Thus, the name of product formed is $\text{Cyclooct}-4-\text{enone}$.

Conclusion

The product formed for the given reaction is $\text{Cyclooct}-4-\text{enone}$.

Interpretation Introduction

(b)

Interpretation: The product formed for the given reaction is to be drawn.

Concept introduction: Curved arrows aid in determining the movement and flow of electrons in the reaction. The electrons that take part in the chemical reactions are shown by the curved arrows.

In the sigmatropic rearrangement, the rearrangement of pi bond and the breaking of sigma bond take place. This results in the generation of new sigma bond in the product. In this type of rearrangement, the number of pi bonds remains constant in the reactant as well as in the product.

Answer to Problem 27.50P

The product formed for the given reaction is $\text{Bicyclo}\left[\mathrm{5.3.1}\right]\text{undec}-3-\text{en}-11-\text{one}$ shown below.

Explanation of Solution

The given reaction is shown below.

Figure 3

The product formed for the given reaction is shown below.

Figure 4

The first step in the given reaction is the formation of enolate ion. The curved arrows show the movement of pi bonds to give the final product. In the next step, the compound undergoes to the $\left[3,3\right]$ sigmatropic rearrangement in which old sigma bond breaks and results in the formation of new sigma bonds to give the desired product.

Thus, the product formed for the given reaction is $\text{Bicyclo}\left[\mathrm{5.3.1}\right]\text{undec}-3-\text{en}-11-\text{one}$.

Conclusion

The product formed for the given reaction is $\text{Bicyclo}\left[\mathrm{5.3.1}\right]\text{undec}-3-\text{en}-11-\text{one}$.

Interpretation Introduction

(c)

Interpretation: The product formed for the given reaction is to be drawn.

Concept introduction: Curved arrows aid in determining the movement and flow of electrons in the reaction. The electrons that take part in the chemical reactions are shown by the curved arrows.

In the sigmatropic rearrangement, the rearrangement of pi bond and the breaking of sigma bond take place. This results in the generation of new sigma bond in the product. In this type of rearrangement, the number of pi bonds remains constant in the reactant as well as in the product.

Answer to Problem 27.50P

The product formed for the given reaction is $2-\left(2-\text{methylenecyclohexyl}\right)\text{phenol}$ shown below.

Explanation of Solution

The given reaction is shown below.

Figure 5

The product formed for the given reaction is shown below.

Figure 6

In the given reaction, curved arrows shows the movement of pi bonds to give the final product. In this type of reaction, the compound undergoes to the $\left[3,3\right]$ sigmatropic rearrangement in which old sigma bond breaks and results in the formation of new sigma bonds to give the desired product.

Thus, the name of product formed is $2-\left(2-\text{methylenecyclohexyl}\right)\text{phenol}$.

Conclusion

The product formed for the given reaction is $2-\left(2-\text{methylenecyclohexyl}\right)\text{phenol}$.

Interpretation Introduction

(d)

Interpretation: The product formed for the given reaction is to be drawn.

Concept introduction:

Answer to Problem 27.50P

The product formed for the given reaction is,

Explanation of Solution

The given reaction is shown below.

Figure 7

The molecular formula of the product is ${\text{C}}_{\text{7}}{\text{H}}_{\text{8}}$.

The product formed for the given reaction is shown below.

Figure 8

The given reactant undergoes $\left[2+2\right]$ cycloaddition reaction to give the desired product.

Conclusion

The product formed for the given reaction is shown in Figure 8.