Chapter 24, Problem 30P

Interpretation Introduction

Interpretation:

The given carbohydrates are to be classified for the given conditions.

Concept introduction:

A five membered closed chain form of a monosaccharide is furanose while a six membered closed chain form of a monosaccharide is pyranose.

For a sugar drawn in the Fischer projection, if the hydroxyl group on the bottom chiral center points to the right, it is referred as D-sugar. If the hydroxyl group on the bottom chiral center point to the left, it is referred as L-sugar.

Carbohydrates that have a carbon substituent attached to the main chain are branched chain sugars.

Carbohydrates having a keto functional group in their open-chair form are called ketoses.

In deoxy sugars, the hydroxyl group is replaced by hydrogen.

In cyclic form of sugar the carbon atom, that is, the carbonyl carbon in the open chain form is the anomeric carbon.

The configuration at the anomeric carbon atom in maltose is variable and may be either $\alpha \text{ or }\beta$.

In two stereoisomeric chair forms of a carbohydrate, one form has anomeric hydroxyl group in equatorial orientation (above the plane), called beta form, and the other has hydroxyl group in the axial position (below the plane), called an alpha form.