Draw Fischer projections of the following molecules.
(b)

Verified step by step guidance

1. Understand the Fischer projection: A Fischer projection is a two-dimensional representation of a molecule where the vertical lines represent bonds going away from the viewer (into the plane), and the horizontal lines represent bonds coming toward the viewer (out of the plane). The carbon chain is arranged vertically, with the most oxidized carbon (e.g., a carbonyl group) at the top.
2. Identify the stereocenters in the molecule: Look for carbons that are bonded to four different groups. These are the chiral centers that will determine the stereochemistry of the Fischer projection.
3. Assign the configuration (R or S) to each stereocenter: Use the Cahn-Ingold-Prelog priority rules to assign priorities to the groups attached to each stereocenter. Then, determine the configuration based on the arrangement of these groups.
4. Draw the Fischer projection: Place the most oxidized carbon (e.g., aldehyde or ketone group) at the top of the vertical line. Arrange the substituents on the horizontal and vertical lines according to the stereochemistry determined in the previous step. Ensure that the horizontal substituents are coming out of the plane and the vertical substituents are going into the plane.
5. Double-check the stereochemistry: Verify that the Fischer projection correctly represents the stereochemistry of the molecule by mentally converting it back to a three-dimensional structure and confirming the configurations of the stereocenters.

Key Concepts

Fischer Projections

Fischer projections are a two-dimensional representation of three-dimensional organic molecules, particularly useful for depicting carbohydrates and amino acids. In these projections, vertical lines represent bonds that extend away from the viewer, while horizontal lines indicate bonds that come towards the viewer. This format helps in visualizing stereochemistry and understanding the spatial arrangement of substituents around chiral centers.

Chirality

Chirality refers to the property of a molecule that has non-superimposable mirror images, much like left and right hands. Molecules that possess chirality typically have one or more chiral centers, usually carbon atoms bonded to four different substituents. Understanding chirality is crucial for accurately drawing Fischer projections, as it determines the orientation of the substituents in the projection.

Stereochemistry

Stereochemistry is the study of the spatial arrangement of atoms in molecules and how this arrangement affects their chemical properties and reactions. It encompasses concepts such as enantiomers, diastereomers, and geometric isomers. In the context of Fischer projections, stereochemistry is vital for correctly representing the 3D orientation of substituents around chiral centers, which influences the molecule's behavior in biological systems.