Fischer Projections in Organic Chemistry

Fischer Projections

Fischer projections are a method of representing the three-dimensional structure of a molecule in a two-dimensional form.

Key Features:

• Vertical bonds: In a Fischer projection, vertical bonds are coming out of the plane of the paper, while horizontal bonds are going into the plane of the paper.
• Stereochemistry: Fischer projections are used to depict the stereochemistry of a molecule, which is the arrangement of atoms in space.

Drawing Fischer Projections:

• Start by drawing a horizontal bond, which represents the backbone of the molecule.
• Add vertical bonds, which represent the substituents attached to the backbone.
• Identify the stereocenter (the central atom) and arrange the substituents around it.
• Use wedges and dashes to indicate the stereochemistry of the molecule.

Interpreting Fischer Projections:

• Wedges: A wedge () indicates a bond coming out of the plane of the paper.
• Dashes: A dash (-) indicates a bond going into the plane of the paper.
• Solid lines: Solid lines represent bonds in the plane of the paper.
• R/S configuration: Fischer projections can be used to determine the R/S configuration of a molecule.

Syn and Anti Configurations:

• Syn configuration: In a syn configuration, two substituents are on the same side of the molecule.
• Anti configuration: In an anti configuration, two substituents are on opposite sides of the molecule.
• Fischer projections can be used to determine the syn/anti configuration of a molecule by examining the arrangement of substituents around the stereocenter.