Chapter 5, Problem 5.62P

Interpretation Introduction

(a)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is enantiomers.

Explanation of Solution

The given pair of compounds is,

Figure 1

The given compounds have same connectivity of atoms or groups but have opposite configuration at the stereogenic centre. Hence, the given pair of compounds is enantiomers.

Conclusion

The given pair of compounds is enantiomers.

Interpretation Introduction

(b)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is constitutional isomers.

Explanation of Solution

The molecular formula of both given compounds is ${\text{C}}_{\text{7}}{\text{H}}_{\text{14}}$. However, the structural arrangement of atoms is different in both compounds. Two compounds that have same molecular formula but different structural arrangement of atoms are termed as constitutional isomers. Therefore, the given pair of compounds is constitutional isomers.

Conclusion

The given pair of compounds is constitutional isomers.

Interpretation Introduction

(c)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is diastereomers.

Explanation of Solution

The given pair of compounds is,

Figure 2

The given compounds have one stereogenic centre with same configuration and one with opposite configuration as shown in Figure 2. Hence, the given pair of compounds is diastereomers.

Conclusion

The given pair of compounds is diastereomers.

Interpretation Introduction

(d)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is not isomers of each other.

Explanation of Solution

The molecular formula of given compounds is different from the each other. The molecular formula of one is ${\text{C}}_{\text{8}}{\text{H}}_{\text{10}}$ and other is ${\text{C}}_{\text{8}}{\text{H}}_{\text{12}}$. Therefore, the given pair of compounds is not isomers of each other.

Conclusion

The given pair of compounds is not isomers of each other.

Interpretation Introduction

(e)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is enantiomers.

Explanation of Solution

The given pair of compounds is,

Figure 3

The given compounds have opposite configurations at the two stereogenic centre as shown in Figure 3. Hence, the given pair of compounds is enantiomers.

Conclusion

The given pair of compounds is enantiomers.

Interpretation Introduction

(f)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is enantiomers.

Explanation of Solution

The given pair of compounds is,

Figure 4

In the given compounds, $\text{Cl}$, $\text{Br}$, $\text{I}$ and $\text{H}$ atoms are attached to carbon atom. The atomic number of $\text{Br}$, $\text{Cl}$ and $\text{I}$ is $35$, $17$ and $53$, respectively. Hence, the highest priority group is $\text{I}$ as shown in Figure 4. Complete the circle in decreasing order of priority from $1\to 2\to 3$.

Thus, the two compounds have opposite configurations. Hence, the given pair of compounds is enantiomers.

Conclusion

The given pair of compounds is enantiomers.

Interpretation Introduction

(g)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is identical.

Explanation of Solution

The given pair of compounds is,

Figure 5

The given compounds have same connectivity and same configurations at the two stereogenic centre as shown in Figure 5. Hence, the given pair of compounds is identical.

Conclusion

The given pair of compounds is identical.

Interpretation Introduction

(h)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is diastereomers.

Explanation of Solution

The given pair of compounds is,

Figure 6

The given compounds have one stereogenic centre with same configuration and one with opposite configuration as shown in Figure 6. Hence, the given pair of compounds is diastereomers.

Conclusion

The given pair of compounds is diastereomers.

Interpretation Introduction

(i)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is diastereomers.

Explanation of Solution

The given pair of compounds is,

Figure 7

Two methyl groups present on the six membered ring are above the plane. However, the methyl groups of chair conformation are present trans to each other. Therefore, the given pair of compounds represents diastereomers.

Conclusion

The given pair of compounds is diastereomers.

Interpretation Introduction

(j)

Interpretation: The relation between given pair of compounds is to be determined.

Concept introduction: The stereogenic centers with $R,S$ configuration are assigned according to Cahn-Ingold-Prelog rules. According to these rules, the substituents attached to stereogenic centers are given priority. On moving from higher priority to lower priority substituent in clockwise direction, the compound is assigned with $R$ configuration. On moving from higher priority to lower priority substituent in anticlockwise direction, the compound is assigned with $S$ configuration.

Enantiomer of a compound has opposite configuration at stereogenic centers. Diastereomers of a compound have at least one stereogenic centre with same configuration and at least one with opposite configuration.

Answer to Problem 5.62P

The given pair of compounds is constitutional isomers.

Explanation of Solution

The given pair of compounds is,

Figure 8

In the given compounds, the position of $\text{OH}$ and $\text{Br}$ is different. The molecular formula of both compounds is same only the arrangement of atoms is different. Therefore, the given pair of compounds is constitutional isomers of each other.

Conclusion

The given pair of compounds is constitutional isomers.