Chapter 25, Problem 25.23P

(a)

Interpretation Introduction

Interpretation:

The specific rotation of α-L-glucose has to be given.

Concept Introduction:

The carbohydrates have D-monosaccharide and L-monosaccharide, which shows specific rotation based on their rotations.  The D-monosaccharide shows specific rotation with the sign +.  Whereas, the L-monosaccharide shows specific rotation with the sign −.

(b)

Interpretation Introduction

Interpretation:

If α-L-glucose is dissolved in water, the specific rotation value will change or not and if changes, to what value has to be given.

Concept Introduction:

When carbohydrates are dissolved in water, the anomeric forms are interconverted (α-form to β-form) to attain equilibrium.  This interconversion of the anomers is said to be mutarotation.