Chapter 5, Problem 5.67P

Interpretation Introduction

Interpretation:

Based on Fischer proof, the aldopentoses structures and aldehexose structures that could be ruled out for $\text{D-arabinose}$ and $\text{D-glucose}$ are to be determined

Concept introduction:

Aldoses and ketoses can be oxidized using nitric acid. Upon oxidation, both carbon atoms, at the end, are oxidized to $\text{COOH}$ group. A chiral compound contains at least one carbon which is bonded to four different atoms or groups. A chiral compound does not have any elements of symmetry. Molecules containing two identical chiral centers can be achiral. A molecule containing two or more equivalent chiral centers and an internal plane of symmetry or a center of symmetry is called a meso isomer or compound. Meso compounds are not optically active.

In carbohydrate chemistry the chain contraction method for aldoses is Wohl degradation. In this reaction, the carbon chain is reduced by one. By using this reaction, $\text{D-glucose}$ is converted to $\text{D-arabinose}$. D-sugar is one in which the $\text{OH}$ group attached to the highest numbered chirality center is present on the right side of the vertical chain in Fischer projection.