Q. 13.39 - An Introduction to General, Organic, and Biological Chemistry

Question

Draw the Fischer projection for the oxidation and the reduction products of D-arabinose. What are the names of the sugar acid and the sugar alcohol produced?

Step-by-Step Solution

Answer

The oxidation and the redution products

Step 1: Given information

The product is 

Step 2 : An Introduction

Redox reactions occur when the oxidation states of the substrate change. The loss of electrons or an increase in the oxidation state of a chemical or atoms within it is referred to as oxidation. Reduction is the addition of electrons or a reduction in the oxidation state of a chemical or its atoms.

Step 3: Determine the Fisher projection model

Emil Fischer created the Fischer projection model, which shows the three-dimensional structure of enantiomers. The horizontal lines in the structure represent forward bonds, whereas the vertical lines represent backward bonds from a carbon atom.

The top is most likely oxidised carbon, and the core carbon atom to which the other groups are linked is often chiral carbon.

The location of the hydroxyl group $-OH$ in the structure distinguishes the levo rotatory $L$ and dextro rotatory (D) forms of enantiomers. The L-isomer is represented by drawing the hydroxyl group linked to the chiral carbon to the left. The $D$-isomer is shown by drawing the hydroxyl group to the right.

Step 4: Determine the oxidation and reduction products

D-Arabinose is a five carbon aldose sugar. Aldehydes upon reduction produces alcohols; and oxidation of aldehydes gives carboxylic acids.

Upon reduction (addition of hydrogen), D-Arabinose produces $D$-Arabitol, which is a five carbon alcohol. Oxidation (addition of oxygen) of D-arabinose produces $D$-arabinonic acid.

Step 5: Determine the Structure