Chapter 16, Problem 16.11P

Neuroprotectin D1 (NPD1) is synthesized in the body from highly unsaturated essential fatty acids. NPD1 is a potent natural anti-inflammatory agent.

NPD1

a. Label each double bond as conjugated or isolated.

b. Label each double bond as E or Z.

c. For each conjugated system, label the given conformation as s-cis or s-trans.

Interpretation Introduction

(a)

Interpretation: Neuroprotectin D1 is synthesized in the body from highly unsaturated essential fatty acids. NPD1 is a potent natural anti-inflammatory agent. The each double bond in NPD1 is to be labeled as conjugated or isolated.

Concept introduction: Diene is a hydrocarbon that contains two $\text{C}=\text{C}$ double bonds in a compound.

Conjugated diene consists of two double bonds that are separated by a single bond, whereas isolated diene also consists of two double bond but they are separated by two more carbon atoms.

The example that shows the basic difference between conjugated diene and isolated diene is shown below.

Figure 1

In conjugated diene, electrons in the pi bonds are delocalized, whereas in isolated diene, electrons in the pi bonds are localized.

Answer to Problem 16.11P

The each double bond in NPD1 as conjugated and isolated diene is shown below.

Figure 3

The double bond present between $\text{C}4-\text{C}5$, $\text{C7}-\text{C8}$ and $\text{C19}-\text{C20}$ are isolated, whereas double bond present between $\text{C11}-\text{C12}$, $\text{C13}-\text{C14}$ and $\text{C15}-\text{C16}$ are conjugated.

Explanation of Solution

The given structure of NPD1 is shown below.

Figure 2

Diene is a hydrocarbon that contains two $\text{C}=\text{C}$ double bonds in a compound.

Conjugated diene consists of two double bonds that are separated by a single bond, whereas isolated diene also consists of two double bond but they are separated by two more carbon atoms. Therefore, carbon atoms of a conjugated double bond are $s{p}^2$ hybridized, whereas carbon atoms of a isolated double bond is one or more $s{p}^3$ hybridized.

The each double bond in NPD1 as conjugated and isolated diene is shown below.

Figure 3

The double bond present between $\text{C}4-\text{C}5$, $\text{C7}-\text{C8}$ and $\text{C19}-\text{C20}$ are isolated, whereas double bond present between $\text{C11}-\text{C12}$, $\text{C13}-\text{C14}$ and $\text{C15}-\text{C16}$ are conjugated.

Conclusion

The each double bond in NPD1 as conjugated or isolated is rightfully stated.

Interpretation Introduction

(b)

Interpretation: Neuroprotectin D1 is synthesized in the body from highly unsaturated essential fatty acids. NPD1 is a potent natural anti-inflammatory agent. The each double bond in NPD1 is to be labeled as $E$ or $Z$.

Concept introduction: The prefix $E$ and $Z$ depends upon the location of the higher priority groups. When two higher priority groups are present on the opposite side then it is an $E$ isomer, whereas when two higher priority groups are present on the same side then it is $Z$ isomer.

Answer to Problem 16.11P

The each double bond in NPD1 as conjugated and isolated diene is shown below.

Figure 4

The double bond present between $\text{C}4-\text{C}5$, $\text{C7}-\text{C8}$ and $\text{C19}-\text{C20}$ have $Z$ conformation, whereas double bond present between $\text{C11}-\text{C12}$, $\text{C13}-\text{C14}$ are have $E$ conformation.

Explanation of Solution

The given structure of NPD1 is shown below.

Figure 2

The prefix $E$ and $Z$ depends upon the location of the higher priority groups. When two higher priority groups are present on the opposite side then it is an $E$ isomer, whereas when two higher priority groups are present on the same side then it is $Z$ isomer.

The each double bond in NPD1 as conjugated and isolated diene is shown below.

Figure 4

The double bond present between $\text{C}4-\text{C}5$, $\text{C7}-\text{C8}$ and $\text{C19}-\text{C20}$ have $Z$ conformation, whereas double bond present between $\text{C11}-\text{C12}$, $\text{C13}-\text{C14}$ are have $E$ conformation.

Conclusion

The each double bond in NPD1 as $E$ or $Z$ is rightfully stated.

Interpretation Introduction

(c)

Interpretation: Neuroprotectin D1 is synthesized in the body from highly unsaturated essential fatty acids. NPD1 is a potent natural anti-inflammatory agent. For each conjugated system in NPD1 is to be labeled as $\text{s}-\text{cis}$ or $\text{s}-\text{trans}$ conformation.

Concept introduction: “If the two double bonds are on the same side of the single bond joining the two double bonds, then it is known as $\text{s}-\text{cis}$ conformation, whereas if the two double bonds are on the opposite side of the single bond joining the two double bonds, then it is known as $\text{s}-\text{trans}$ conformation.”

Answer to Problem 16.11P

The each double bond in NPD1 as conjugated and isolated diene is shown below.

Figure 3

The double bond present between $\text{C11}-\text{C12}$, $\text{C13}-\text{C14}$ and $\text{C15}-\text{C16}$ are conjugated. The double bonds between $\text{C11}-\text{C12}$ and $\text{C13}-\text{C14}$ are on same side of the single bond $\text{C12}-\text{C13}$ and thus, have $\text{s}-\text{cis}$ conformation.

The double bonds between $\text{C13}-\text{C14}$ and $\text{C15}-\text{C16}$ are on opposite side of the single bond $\text{C14}-\text{C15}$ and thus, have $\text{s}-\text{trans}$ conformation.

Explanation of Solution

The given structure of NPD1 is shown below.

Figure 2

“If the two double bonds are on the same side of the single bond joining the two double bonds, then it is known as $\text{s}-\text{cis}$ conformation, whereas if the two double bonds are on the opposite side of the single bond joining the two double bonds, then it is known as $\text{s}-\text{trans}$ conformation.”

The each double bond in NPD1 as conjugated and isolated diene is shown below.

Figure 3

The double bond present between $\text{C11}-\text{C12}$, $\text{C13}-\text{C14}$ and $\text{C15}-\text{C16}$ are conjugated. The double bonds between $\text{C11}-\text{C12}$ and $\text{C13}-\text{C14}$ are on same side of the single bond $\text{C12}-\text{C13}$ and thus, have $\text{s}-\text{cis}$ conformation.

The double bonds between $\text{C13}-\text{C14}$ and $\text{C15}-\text{C16}$ are on opposite side of the single bond $\text{C14}-\text{C15}$ and thus, have $\text{s}-\text{trans}$ conformation.

Conclusion

The $\text{s}-\text{cis}$ and $\text{s}-\text{trans}$ conformation for each conjugated system in NPD1 is rightfully stated.