Draw the simple Fischer projection formulae of D - ( + ) glucose and D - ( - ) fructose.

To illustrate the Fischer projection formulas of D-(+)-glucose and D-(-)-fructose, we can represent these sugars in a two-dimensional format that highlights their stereochemistry.

D-(+)-Glucose Fischer Projection

D-(+)-glucose is an aldohexose, meaning it has an aldehyde group and six carbon atoms. Its Fischer projection can be depicted as follows:

• Carbon 1: Aldehyde group (CHO)
• Carbon 2: Hydroxyl group (OH) on the right
• Carbon 3: Hydroxyl group (OH) on the right
• Carbon 4: Hydroxyl group (OH) on the left
• Carbon 5: Hydroxyl group (OH) on the right
• Carbon 6: CH2OH group

The structure looks like this:

    CHO
     |
    H-C-OH
     |
    HO-C-H
     |
    H-C-OH
     |
    H-C-OH
     |
    CH2OH

D-(−)-Fructose Fischer Projection

D-(−)-fructose is a ketohexose, which means it contains a ketone group. Its Fischer projection is represented as follows:

• Carbon 2: Ketone group (C=O)
• Carbon 3: Hydroxyl group (OH) on the right
• Carbon 4: Hydroxyl group (OH) on the left
• Carbon 5: Hydroxyl group (OH) on the right
• Carbon 6: CH2OH group

The structure appears as:

      O
      ||
    H-C-H
      |
    HO-C-H
      |
    H-C-OH
      |
    CH2OH

These Fischer projections help visualize the spatial arrangement of atoms in these important carbohydrates.