Chapter 28, Problem 28.42P

Interpretation Introduction

(a)

Interpretation: The relationship between and is to be stated.

Concept introduction: The anomers are cyclic monosaccharides, which differ in configuration at one stereogenic centre. These carbon atoms are called anomeric centre.

Answer to Problem 28.42P

The compounds and are epimers.

Explanation of Solution

The structures of compounds and are,

Figure 1

In the given structures, the configuration at is different. Hence, the compounds and are epimers.

Conclusion

The compounds and are epimers.

Interpretation Introduction

(b)

Interpretation: The relationship between and is to be stated.

Concept introduction: The anomers are cyclic monosaccharides, which differ in configuration at one stereogenic centre. These carbon atoms are called anomeric centre. The compounds which are neither mirror images nor supperimposable on each other are known as diastereomer.

Answer to Problem 28.42P

The compound and are diastreomers but not epimers.

Explanation of Solution

The structures of given compound and are,

Figure 2

In the given structures, the compound is not mirror image of compound and the configuration of more than is different. Hence, the compound and are diastreomers but not epimers.

Conclusion

The compound and are diastreomers but not epimers.

Interpretation Introduction

(c)

Interpretation: The relationship between and is to be stated.

Concept introduction: The compounds which are mirror images as well as non-supperimposable on each other. These compounds are known as enantiomers.

Answer to Problem 28.42P

The compound and are enantiomers.

Explanation of Solution

The structures of given compound and are,

Figure 3

In the given structures, the compound is mirror image of compound . Hence, the compound and are enantiomers.

Conclusion

The compound and are enantiomers.

Interpretation Introduction

(d)

Interpretation: The relationship between and is to be stated.

Concept introduction: The compounds which have same molecular formula but differ in connectivity of the substituents. These compounds are known as constitutional isomers.

Answer to Problem 28.42P

The compound and are constitutional isomers.

Explanation of Solution

The structures of given compound and are,

Figure 4

In the given structures, the molecular formula of is same to the molecular formula of but the connectivity of substituents at is different. Hence, the compound and are constitutional isomers.

Conclusion

The compound and are constitutional isomers.

Interpretation Introduction

(e)

Interpretation: The relationship between and is to be stated.

Concept introduction: The anomers are cyclic monosaccharides, which differ in configuration at one stereogenic centre. These carbon atoms are called anomeric centre. The compounds which are neither mirror images nor supperimposable on each other are known as diastereomer.

Answer to Problem 28.42P

The compounds and are diastreomers but not epimers.

Explanation of Solution

The substituents on a carbon are present above the ring in Haworth projection indicates that these bonds are above the plane (i.e. either equatorial or axial position) in chair form. The structures of given compound and are,

Figure 5

In the given structures, the configuration at is different which shows that the compound is not mirror image of compound and. Hence, the compound and are diastreomers but not epimers.

Conclusion

The compounds and are diastreomers but not epimers.