Chapter 9, Problem 7P

Interpretation Introduction

Interpretation:

Haworth projection of a dextran including $\left(1\to 3\right)$ branch point should be drawn.

Concept introduction:

A Haworth projection is common way to represent the cyclic structure of monosaccharides.

Five and six membered hemiacetals are represented as planar pentagons or hexagons.

$\text{α}$ form of the Haworth projection indicates, the exocyclic O group at the anomeric center is on the opposite face as to the ${\text{CH}}_{\text{2}}\text{OH}$ group.

$\text{β}$ form of the Haworth projection, the exocyclic O group at the anomeric center is on the same face as to the ${\text{CH}}_{\text{2}}\text{OH}$ group.

In the Haworth projection ${\text{CH}}_{\text{2}}\text{OH}$ group is present in the RIGHT side of the ring is called D- form.

In the Haworth projection ${\text{CH}}_{\text{2}}\text{OH}$ group is present in the LEFT side of the ring is called L- form.

For example:

Haworth projections of glucose:

Pictorial representation: