Chapter 5, Problem 15PP

Interpretation Introduction

Interpretation:

The percent enantiomeric excess and the enantiomer that is in excess are to be determined.

Concept introduction:

The molecules that are non-superimposable or not identical with their mirror images are known as chiral molecules. Chiral molecules have the capability to rotate plane-polarized light.

A pair of mirror images that are non-identical is known as a pair of enantiomers.

The enantiomers in which the path traced from the highest to the lowest atomic number is in the anticlockwise direction are designated as $S$ provided that among the four groups attached to the chiral carbon, the least priority group is in horizontal position in Fischer projection.

The enantiomers in which the path traced from the highest to the lowest atomic number is in the clockwise direction are designated as $R$ provided that among the four groups attached to the chiral carbon, the least priority group is in horizontal position in Fischer projection.

In a solution, as light is passed through a sample, the orientation of the monochromatic plane-polarized light changes. This change is known as specific rotation $\left(\left[\alpha \right]\right)$.

The difference between the values of mole fractions of two enantiomers is called the enantiomeric excess.