9. Amity Institute of Biotechnology
Fischer Projections
• Used to represent carbohydrates (chiral carbons)
• Places the most oxidized group at the top (C1)
• Uses horizontal lines for bonds that come forward
• Uses vertical lines for bonds that go back
FIGURE 7-2 (part 1) Three ways to represent the two enantiomers of glyceraldehyde. The enantiomers are mirror images of each other. Ball-and-stick models show the actual configuration of molecules. Recall (see Figure 1-17) that in perspective formulas, solid wedge-shaped bonds point toward the reader, dashed wedges point away.
FIGURE 7-7 Pyranoses and furanoses. The pyranose forms of D-glucose and the furanose forms of D-fructose are shown here as Haworth perspective formulas. The edges of the ring nearest the reader are represented by bold lines. Hydroxyl groups below the plane of the ring in these Haworth perspectives would appear at the right side of a Fischer projection (compare with Figure 7-6). Pyran and furan are shown for comparison.