Chapter 24, Problem 87IP

Interpretation Introduction

Interpretation:

The more stable chair conformation of α -pyranoseform of L-idose should be drawn and the reason behind in ${\text{CH}}_{\text{2}}\text{OH}$ group of D-idose, occupies an axial position in the more stable chair conformation should be explained.

Concept introduction:

The Fischer projection: Fischer projection is a two-dimensional representation of a three-dimensional organic molecule by projection. It is mainly proposed for the representation of carbohydrate chemistry.

The orientation of the carbon atoms in a molecule is arranged vertically from top to bottom.

The C1 carbon is at the top of the orientation, the hydrogen and hydroxyl groups are placed in right and left side of the orientation. D and L form are depends on the arrangement of the hydroxyl group. If the hydroxyl group is in the right side of the molecule in the penultimate (next-to-last) carbon is called as D sugar, if the If the hydroxyl group is in the left side of the molecule in the penultimate (next-to-last) carbon is called as L sugar.

To find: The more stable chair conformation of α -pyranoseform of L-idose. The reason of ${\text{CH}}_{\text{2}}\text{OH}$ group in D-idose, occupies an axial position in the more stable chair conformation