In isomerism how to draw fisher projection? | Chemistry - Fischer Projection | SolveeIt

Question

In isomerism how to draw fisher projection?

Answer

To draw a Fischer projection:

Orient the molecule so the main carbon chain is vertical, with the top and bottom groups pointing away from you.
Ensure groups on the horizontal line point towards you.
Draw a cross for each chiral center, placing the vertical and horizontal groups accordingly.

Explanation

Solution

To draw a Fischer projection, follow these conventions:

Orient the Molecule: Mentally rotate the 3D structure (e.g., a wedge-dash representation) so that:
- The main carbon chain (usually the longest continuous chain or the one containing the principal functional group) is positioned vertically.
- The groups at the top and bottom of the vertical chain are pointing away from the viewer (into the plane of the paper).
- The groups on the horizontal line at a chiral center are pointing towards the viewer (out of the plane of the paper).
Draw the Cross: For each chiral carbon, draw a cross (+). The intersection of the horizontal and vertical lines represents the chiral carbon atom.
Place the Substituents:
- Place the groups that were pointing away (from the vertical chain) on the vertical line of the Fischer projection.
- Place the groups that were pointing towards (from the horizontal plane at the chiral center) on the horizontal line of the Fischer projection.
Highest Priority at Top (for multi-chiral compounds): For molecules with multiple chiral centers (like carbohydrates), the carbon with the highest oxidation state or the highest priority group according to IUPAC rules (e.g., an aldehyde group) is typically placed at the top of the vertical line.

Example: Drawing the Fischer Projection of (R)-2-butanol

Identify Chiral Center and Main Chain: The chiral center is C2. The main chain is CH3-CH(OH)-CH2-CH3.
Orient the 3D structure: Imagine (R)-2-butanol such that the CH3 group is at the top (pointing away) and the CH2CH3 group is at the bottom (pointing away). In this specific orientation for (R)-2-butanol, the -OH group will be on the right (pointing towards you), and the -H atom will be on the left (pointing towards you).
```
          CH3 (pointing away)
            |
H (pointing towards) --- C* --- OH (pointing towards)
            |
        CH2CH3 (pointing away)
```
Draw the Fischer Projection: Flatten this 3D orientation onto a 2D plane.
```
      CH3
       |
H -----C----- OH
       |
     CH2CH3
```
Here, the intersection represents the chiral C2 atom.

Fischer projection is a 2D representation of a 3D chiral molecule. The key conventions are: vertical lines for bonds pointing away, horizontal lines for bonds pointing towards the viewer. The main carbon chain is placed vertically, usually with the highest priority group at the top. Each intersection represents a chiral carbon.

Question: In isomerism how to draw fisher projection?...

Solution