Chapter 18.10, Problem 1QQ

Interpretation Introduction

Interpretation:

The number of different forms of a D-monosaccharide which are present at equilibrium in an aqueous solution of the monosaccharide has to be predicted

Concept introduction:

Open chain structures of monosaccharides which contain five or more carbon atoms exist in equilibrium with two cyclic structures.  These cyclic structures are the dominating forms at equilibrium.  The carbonyl group in the open-chain structure of monosaccharide reacts intramolecularly with a hydroxyl group which results in the formation of cyclic forms.  These cyclic compounds are called cyclic hemiacetals.