Chapter 16, Problem 86P

(a)

Interpretation Introduction

Interpretation:

The six-membered ring structures of D-glucose has to be drawn.

Concept introduction:

Glucose is a monosaccharide with a molecular formula ${\text{C}}_{\text{6}}{\text{H}}_{\text{12}}{\text{O}}_{\text{6}}$.  It can exist both as an open-chain structure and a cyclic structure.  It has 16 aldohexose stereoisomers and D-glucose is one of them.  It occurs more widely in nature than L-glucose.  The intramolecular nucleophilic addition reaction between the aldehyde group and hydroxyl group forms a hemiacetal linkage which results in the cyclic ring structure.

(b)

Interpretation Introduction

Interpretation:

The major six-membered ring product of D-glucose has to be given.

Concept introduction:

Glucose is a monosaccharide with a molecular formula ${\text{C}}_{\text{6}}{\text{H}}_{\text{12}}{\text{O}}_{\text{6}}$.  It can exist both as an open-chain structure and a cyclic structure.  It has 16 aldohexose stereoisomers and D-glucose is one of them.  It occurs more widely in nature than L-glucose.  The intramolecular nucleophilic addition reaction between the aldehyde group and hydroxyl group forms a hemiacetal linkage which results in the cyclic ring structure.