Exercise 5 | Carbohydrates

The objective of this exercise is to determine the structure of D-xylose.

D-xylose is an aldopentose, which gives an optically inactive product after its oxidation with dilute nitric acid.
The Kiliani-Fischer synthesis on D-xylose leads to two different hexoses, optically active after their oxidation with dilute nitric acid.

Draw the structure of D-xylose.

 

Kiliani-Fischer synthesis:
 

D-xylose is an aldopentose:
 

D-xylose is D configuration:
 

 

Its oxidation with dilute nitric acid gives an optically inactive product:
 

 

The Kiliani-Fischer synthesis on D-xylose leads to two different hexoses, optically active after their oxidation with dilute nitric acid: