Chapter 24, Problem 48DSP

Interpretation Introduction

Interpretation:

Correct structures for the hexose that gives the same aldaric acid as $\text{(+)-glucose}$ is to be chosen.

Concept introduction:

The stereoisomers that are not mirror images are diastereomers.

They differ in absolute configuration at only one chirality center.

$\text{(+)-glucose}$ and its diasteromeric hexose undergo oxidation at $\text{C-1 and C-6}$ carbon atoms to form optically active aldaric acid.

The aldaric acids have two $\text{-COOH}$ groups at both ends of the carbon chain. There is no way to tell which was originally the $\text{-CHO}$ and which was ${\text{-CH}}_2\text{OH}$, and thus, a given aldaric acid can have two different precursors.