Chapter 25.SE, Problem 42AP

Interpretation Introduction

a)

Interpretation:

Fischer projections of the following molecules are to be given.

The S enantiomer of 2-bromobutane.

Concept introduction:

In Fischer projection formula, a tetrahedral carbon is represented by two crossed lines. The horizontal line represents bonds coming out of the page and vertical lines represent bonds moving in to the page.

For assigning R or S configuration, the four groups attached to the chiral center are arranged in the order of priority by applying sequence rules. The molecule is then oriented in such a way that the group of lowest priority points away from the viewer. If the arrangement of highest priority to second highest priority to third highest priority is clockwise then R configuration is assigned. If the arrangement of highest priority to second highest priority to third highest priority is counterclockwise then S configuration is assigned.

To show:

Fischer projections of the following molecules.

The S enantiomer of 2-bromobutane.

Interpretation Introduction

b)

Interpretation:

Fischer projections of the following molecules are to be given.

The R enantiomer of alanine.

Concept introduction:

In Fischer projection formula, a tetrahedral carbon is represented by two crossed lines. The horizontal line represents bonds coming out of the page and vertical lines represent bonds moving in to the page.

For assigning R or S configuration, the four groups attached to the chiral center are arranged in the order of priority by applying sequence rules. The molecule is then oriented in such a way that the group of lowest priority points away from the viewer. If the arrangement of highest priority to second highest priority to third highest priority is clockwise then R configuration is assigned. If the arrangement of highest priority to second highest priority to third highest priority is counterclockwise then S configuration is assigned.

To show:

Fischer projections of the following molecules.

The R enantiomer of alanine.

Interpretation Introduction

c)

Interpretation:

Fischer projections of the following molecules are to be given.

The R enantiomer of 2-hydroxypropionic acid.

Concept introduction:

In Fischer projection formula, a tetrahedral carbon is represented by two crossed lines. The horizontal line represents bonds coming out of the page and vertical lines represent bonds moving in to the page.

For assigning R or S configuration, the four groups attached to the chiral center are arranged in the order of priority by applying sequence rules. The molecule is then oriented in such a way that the group of lowest priority points away from the viewer. If the arrangement of highest priority to second highest priority to third highest priority is clockwise then R configuration is assigned. If the arrangement of highest priority to second highest priority to third highest priority is counterclockwise then S configuration is assigned.

To show:

Fischer projections of the following molecules.

The R enantiomer of 2-hydroxypropionic acid.

Interpretation Introduction

d)

Interpretation:

Fischer projections of the following molecules are to be given.

The S enantiomer of 3-methylhexane.

Concept introduction:

In Fischer projection formula, a tetrahedral carbon is represented by two crossed lines. The horizontal line represents bonds coming out of the page and vertical lines represent bonds moving in to the page.

For assigning R or S configuration, the four groups attached to the chiral center are arranged in the order of priority by applying sequence rules. The molecule is then oriented in such a way that the group of lowest priority points away from the viewer. If the arrangement of highest priority to second highest priority to third highest priority is clockwise then R configuration is assigned. If the arrangement of highest priority to second highest priority to third highest priority is counterclockwise then S configuration is assigned.

To show:

The S enantiomer of 3-methylhexane.