Chapter 20.2, Problem 3P

a)

Interpretation Introduction

Interpretation:

Whether each of the given structures is $\text{D}$-glyceraldehyde or $\text{L}$-glyceraldehyde is to be stated.

Concept Introduction:

The configurations of carbohydrates are described by the notations “$\text{D}$” and “$\text{L}$”.  In Fischer projection carbon chain is depicted vertically.

All the carbon atoms of the chain are represented by the center of the crossing line.  The functional group like ketone group has the lowest possible priority two and the aldehydic group has the lowest priority one.

Almost all the sugars found in nature are $\text{D}$-sugars. The mirror image of $\text{D}$-sugar is $\text{L}$-sugar.

The notations “$\text{D}$” and “$\text{L}$” are based on the presence of “OH” group.  If the “OH” group attached to the bottommost asymmetric center of a Fischer projection, is on the right then the compound is a $\text{D}$-sugar.  If that same “OH” group is on the left, then the compound is an $\text{L}$-sugar.

b)

Interpretation Introduction

Interpretation:

Whether each of the given structures is $\text{D}$-glyceraldehyde or $\text{L}$-glyceraldehyde is to be stated.

Concept Introduction:

The configurations of carbohydrates are described by the notations “$\text{D}$” and “$\text{L}$”. In Fischer projection carbon chain is depicted vertically.  All the carbon atoms of the chain are represented by the center of the crossing line.

The functional group like ketone group has the lowest possible priority two and the aldehydic group has the lowest priority one.

Almost all the sugars found in nature are $\text{D}$-sugars. The mirror image of $\text{D}$-sugar is $\text{L}$-sugar.

The notations “$\text{D}$” and “$\text{L}$” are based on the presence of “OH” group. If the “OH” group attached to the bottommost asymmetric center of a Fischer projection, is on the right then the compound is a $\text{D}$-sugar.  If that same “OH” group is on the left, then the compound is an $\text{L}$-sugar.

c)

Interpretation Introduction

Interpretation:

Whether each of the given structures is $\text{D}$-glyceraldehyde or $\text{L}$-glyceraldehyde is to be stated.

Concept Introduction:

The configurations of carbohydrates are described by the notations “$\text{D}$” and “$\text{L}$”. In Fischer projection carbon chain is depicted vertically.  All the carbon atoms of the chain are represented by the center of the crossing line.

The functional group like ketone group has the lowest possible priority two and the aldehydic group has the lowest priority one.

Almost all the sugars found in nature are $\text{D}$-sugars. The mirror image of $\text{D}$-sugar is $\text{L}$-sugar.

The notations “$\text{D}$” and “$\text{L}$” are based on the presence of “OH” group. If the “OH” group attached to the bottommost asymmetric center of a Fischer projection, is on the right then the compound is a $\text{D}$-sugar. If that same “OH” group is on the left, then the compound is an $\text{L}$-sugar.