How To Draw Newman Projections On Chemdraw

Cartoon Fischer Projections

Fischer projections are yet another style to describe molecules. They are normally used in Biochemistry as a uncomplicated manner to draw sugars. However, drawing Fischer projections can be tricky at first. Hither is what a Fischer projection looks like:

This figure is used for drawing Fischer projections. Specifically, glucose is shown in this example going from Fischer projection to bond line structure.

The horizontal bonds are coming out of the page as wedges, while the vertical bonds are going back into the folio every bit dashes. Because all the horizontal bonds are wedges, the Fischer projection is fatigued in the eclipsed configuration.

Many questions nigh drawing Fischer projections in Organic Chemistry require you to get from a Fischer projection to a bond line drawing. They tin can exist tricky, only here is a method that vastly simplifies the process. This procedure works very well and requires almost no mental rotation, i of the hardest things about Orgo for many.

a. Start with a small turn of the molecule. It tin exist in either direction, simply here I have shown it in only one orientation. This is the only step that requires some mental rotation:

There is a carbon atom at each betoken where there is a dash and a wedge, so this molecule has 6 carbons (including the two explicitly shown).

Some people have trouble seeing the way the molecules flip. Likewise, some have trouble seeing how the atoms that were originally on the left side of the Fischer projection become wedges, while those on the right side become dashes. The following figure shows a right hand making precisely the same flip as our molecule. Note that the pollex is pointing to the left at the showtime, and after the flip, information technology points upward.

b. Rotate the molecule 90 degrees. Then, number each carbon.

c. In step b, nosotros saw that we had a vi-carbon chain (this tin change of course depending on the question asked), and then nosotros draw a normal, six-carbon concatenation in bond line form. Notation the orientation afterwards drawing the normal chain. Some are in their "upwards" conformation, while others are in their "down" conformation.

If we apply this up/down system to the concluding construction in role "b," notice that 1 and 6 are downwardly, while 2, iii, 4, and v are upwardly.

d. Now we fill in the groups on each carbon. Find that groups one, 2, and 4 are in the aforementioned orientation for the drawings in b and c (1 is down in each, ii is upwards, and iv is up). This means that the way the atoms are arranged on this carbon stays the same (dashes stay dashes; wedges stay wedges). In 3, 5, and 6, the orientations are flipped (iii and 5 go from up to downward, while 6 goes from down to upwardly), so we must flip the dash and the wedge (wedges turn into dashes; dashes turn into wedges). So on carbon 3, the –OH is a wedge, but after flipping it downward, the –OH now becomes a dash and the –H becomes a wedge. No mental rotation is required here. Just remember that if the configuration changes, then the dashes and wedges change.