Chapter 24, Problem 81IP

(a)

Interpretation Introduction

Interpretation:

The structure of D-gluconic acid should be drawn

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 structure of D-gluconic acid.

(b)

Interpretation Introduction

Interpretation:

The structure of lactone should be drawn and the configuration at eachchirality center identified.

Concept introduction:

The Haworth projection: A Haworth projection is a three-dimensional representation of monosaccharides and the structural formula is inscription as a cyclic structures.

In Haworth projection, oxygen atom is placed in back right corner, ${\text{CH}}_{\text{2}}\text{OH}$ is arranged up at the C5 carbon atom. Anomeric hydroxyl group is placed down if it is α-anomer which is trans to the ${\text{CH}}_{\text{2}}\text{OH}$ of C5 carbon. The remaining hydroxyl group is placed up if the hydroxyl group left side in Fischer projection. Hydroxyl group is placed down if the hydroxyl group right side in Fischer projection

To find: The structure of lactone.

(c)

Interpretation Introduction

Interpretation:

The Optical activity of lactone should be identified.

Concept introduction:

Optical activity: molecule or substances that can rotate the plane-polarized light are said to be optically active.

To find: Optically activity of lactone.

(d)

Interpretation Introduction

Interpretation:

Difference between the D-gluconic acid and the lactone using IR Spectroscopy should be explained

Concept introduction:

Infra-red (IR) spectroscopy: Infra-red (IR) spectroscopy deals with the interaction between a molecule and radiation from the IR region of the electromagnetic spectrum (IR region = 4000 - 400 cm^-1). IR radiation causes the excitation of the vibrations of covalent bonds within that molecule, which include the stretching and bending.

To find: Difference between the D-gluconic acid and the lactone using IR Spectroscopy.