Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

5. Chirality

R and S Configuration

Organic Chemistry

5. Chirality

R and S Configuration

Previous problemNext problem

5:17 minutes

Problem 54

Textbook Question

Chloramphenicol is a broad-spectrum antibiotic that is particularly useful against typhoid fever. What is the configuration of each of its asymmetric centers?

Verified step by step guidance

Step 1: Identify the asymmetric centers in the chloramphenicol molecule. An asymmetric center is a carbon atom bonded to four different groups. In the given structure, there are two asymmetric centers: the first carbon bonded to HO, H, a benzene ring, and another carbon; and the second carbon bonded to CH2OH, H, NH group, and the first carbon.

Step 2: Assign priorities to the substituents attached to each asymmetric center based on the Cahn-Ingold-Prelog (CIP) priority rules. These rules state that the atom with the highest atomic number gets the highest priority. For the first asymmetric center, the groups are HO, H, benzene ring, and the adjacent carbon. For the second asymmetric center, the groups are CH2OH, H, NH group, and the adjacent carbon.

Step 3: Determine the spatial arrangement of the substituents around each asymmetric center. Visualize the molecule in 3D or use the wedge and dash notation provided in the structure. The wedge represents a bond coming out of the plane, and the dash represents a bond going into the plane.

Step 4: Assign the configuration (R or S) to each asymmetric center. To do this, orient the molecule so that the lowest priority group (usually H) is pointing away from you. Then, trace the path from the highest priority group to the second and third priority groups. If the path is clockwise, the configuration is R; if counterclockwise, it is S.

Step 5: Repeat the process for both asymmetric centers and confirm the configurations. For the first asymmetric center, analyze the arrangement of HO, H, benzene ring, and adjacent carbon. For the second asymmetric center, analyze the arrangement of CH2OH, H, NH group, and adjacent carbon.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Asymmetric Centers

Asymmetric centers, or chiral centers, are carbon atoms bonded to four different substituents, leading to non-superimposable mirror images known as enantiomers. The configuration of these centers is crucial in determining the optical activity and biological properties of molecules, such as antibiotics like chloramphenicol.

Stereochemistry

Stereochemistry is the study of the spatial arrangement of atoms in molecules and how this affects their chemical behavior. Understanding stereochemistry is essential for determining the configuration of asymmetric centers, which can influence the efficacy and mechanism of action of compounds like chloramphenicol.

CIP Priority Rules

CIP (Cahn-Ingold-Prelog) priority rules are a set of guidelines used to assign priorities to the substituents attached to an asymmetric center based on atomic number and connectivity. These rules help in determining the R or S configuration of chiral centers, which is vital for accurately describing the structure of chloramphenicol.

Watch next

Master Why stereoisomers need their own naming system. with a bite sized video explanation from Johnny

Start learning