Chapter 23.11, Problem 23.35P

(a)

Interpretation Introduction

Interpretation:

The two possible structures of arabinose are to be shown.

Concept introduction:

Ruff degradation is a method which is used to shorten sugar chain. It is a two step process which starts with a bromine-water oxidation of the aldose to its aldonic acid. Then in the second step, treatment of aldonic acid with hydrogen peroxide and ferric sulfate oxidizes the carbonyl group to ${\text{CO}}_{\text{2}}$ and gives aldose with one carbon atom less. It is used primarily for the determination of structure and synthesis of new sugar.

(b)

Interpretation Introduction

Interpretation:

The structure of erythrose is to be shown.

Concept introduction:

Ruff degradation is a method which is used to shorten sugar chain. It is a two step process which starts with a bromine-water oxidation of the aldose to its aldonic acid. Then in the second step, treatment of aldonic acid with hydrogen peroxide and ferric sulfate oxidizes the carbonyl group to ${\text{CO}}_{\text{2}}$ and gives aldose with one carbon atom less. It is used primarily for the determination of structure and synthesis of new sugar.

(c)

Interpretation Introduction

Interpretation:

The correct structure of arabinose out of the two structures is to be stated and the possible structures of glucose and mannose are to be shown.

Concept introduction:

Glucose and mannose have same molecular formula ${\text{C}}_{\text{6}}{\text{H}}_{\text{12}}{\text{O}}_{\text{6}}$. D-glucose and D-mannose are epimers because they differ only at the position of second carbon atom.

(d)

Interpretation Introduction

Interpretation:

How the interchange of functional groups on D-mannose, which results in the same compound, is the proof of mannose structure and how this implies the correct structure of glucose is to be shown.

Concept introduction:

In $1891$, Emil Fischer determined the structures of glucose and other seven other D-aldohexoses. Fischer, who interchanges the aldehyde group of an aldose to an alcohol, converts the terminal alcohol to an aldehyde to determine the structures of glucose and mannose.

(e)

Interpretation Introduction

Interpretation:

The structure of erythrose is to be shown.

Concept introduction:

In $1891$, Emil Fischer determined the structures of glucose and other seven other D-aldohexoses. Fischer’s who interchanges the aldehyde group of an aldose to an alcohol while converts the terminal alcohol to an aldehyde to determine the structures of glucose and mannose.