Textbook Question
What is the configuration of each of the asymmetric centers in the following compounds?
c.
1
views
Ch. 4 - Isomers: The Arrangement of Atoms in Space
Bruice8th EditionOrganic ChemistryISBN: 9780135213711
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 1)31
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 2)65
- Ch. 2 - Acids and Bases: Central to Understanding Organic Chemistry84
- Ch. 3 - An Introduction to Organic Compounds:Nomenclature, Physical Properties, and Structure183
- Ch. 4 - Isomers: The Arrangement of Atoms in Space121
- Ch. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and Kinetics83
- Ch. 6 - The Reactions of Alkenes • The Stereochemistry of Addition Reactions175
- Ch. 7 - The Reactions of Alkynes • An Introduction to Multistep Synthesis119
- Ch. 8 - Delocalized Electrons: Their Effect on Stability, pKa, and the Products of a Reaction • Aromaticity and Electronic Effects: An Introduction to the Reactions of Benzene148
- Ch. 9 - Substitution and Elimination Reactions of Alkyl Halides212
- Ch. 10 - Reactions of Alcohols, Ethers, Epoxides, Amines, and Sulfur-Containing Compounds131
- Ch. 11 - Organometallic Compounds60
- Ch. 12 - Radicals90
- Ch. 13 - Mass Spectrometry; Infrared Spectroscopy; UV/Vis Spectroscopy62
- Ch. 14 - NMR Spectroscopy95
- Ch. 15 - Reactions of Carboxylic Acids and Carboxylic Acid Derivatives123
- Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives141
- Ch. 17 - Reactions at the Alpha-Carbon101
- Ch. 18 - Reactions of Benzene and Substituted Benzenes144
- Ch. 19 - More About Amines • Reactions of Heterocyclic Compounds49
- Ch. 20 - The Organic Chemistry of Carbohydrates80
- Ch. 21 - Amino Acids, Peptides, and Proteins57
- Ch. 22 - Catalysis in Organic Reactions and in Enzymatic Reactions35
- Ch. 23 - The Organic Chemistry of the Coenzymes—Compounds Derived from Vitamins1
- Ch. 28 - Pericyclic Reactions58
Chapter 5, Problem 101
A student decided that the configuration of the asymmetric centers in a sugar such as D-glucose could be determined rapidly by simply assigning the R configuration to an symmetric center with an OH group on the right and the S configuration to an symmetric center with an OH group on the left. Is he correct?
Verified step by step guidance1
Step 1: Understand the problem. The student is proposing a simplified method to assign R and S configurations to asymmetric centers in D-glucose based on the position of the OH group (right = R, left = S). We need to evaluate whether this approach is correct.
Step 2: Recall the rules for assigning R and S configurations. The Cahn-Ingold-Prelog priority rules are used to determine the configuration of a chiral center. These rules involve assigning priorities to substituents based on atomic number and arranging the molecule so the lowest priority group is pointing away from the observer.
Step 3: Analyze the structure of D-glucose. D-glucose has four asymmetric centers (chiral carbons). The OH groups are positioned on either the right or left side in the Fischer projection. However, the Fischer projection does not directly indicate the spatial arrangement required for R/S determination.
Step 4: Explain why the student's method is incorrect. The configuration (R or S) of a chiral center depends on the 3D spatial arrangement of the substituents, not simply their position in a 2D Fischer projection. The position of the OH group (right or left) in the Fischer projection does not guarantee the correct R/S assignment without applying the priority rules and visualizing the molecule in 3D.
Step 5: Conclude that the student’s method oversimplifies the process and does not account for the necessary application of the Cahn-Ingold-Prelog rules. To correctly assign R and S configurations, the molecule must be analyzed in 3D, and the priorities of all substituents must be considered.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
7mWas 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. In sugars like d-glucose, the configuration at these centers is crucial for determining the molecule's stereochemistry and biological activity. Understanding how to identify and assign configurations at these centers is essential for analyzing sugar structures.
Recommended video:
Guided course
03:38
How to add to asymmetrical double bonds.
Cahn-Ingold-Prelog Priority Rules
The Cahn-Ingold-Prelog (CIP) priority rules are a systematic method for assigning R (rectus) and S (sinister) configurations to chiral centers. These rules dictate that substituents are ranked based on atomic number, with higher atomic numbers receiving higher priority. This systematic approach is necessary to accurately determine the stereochemistry of asymmetric centers, rather than relying on the position of functional groups alone.
Recommended video:
Guided course
01:48Why stereoisomers need their own naming system.
D- and L- Configuration in Sugars
The D- and L- notation in sugars refers to the configuration of the asymmetric carbon farthest from the aldehyde or ketone group. In d-glucose, the D- configuration indicates that the hydroxyl group on this carbon is on the right in a Fischer projection. This notation is essential for distinguishing between different sugar isomers and understanding their biochemical roles, making it important for the student's analysis of d-glucose.
Recommended video:
Guided course
06:47Monosaccharides - D and L Isomerism
Related Practice
Textbook Question
What is the configuration of each of the asymmetric centers in the following compounds?
a.
b.
1
views
Textbook Question
Tamiflu is used for the prevention and treatment of flu. What is the configuration of each of its asymmetric centers?
2
views
Textbook Question
For each pair, indicate which conformer is more stable.
1
views
Textbook Question
Draw the two chair conformers for each of the stereoisomers of trans-1-tert-butyl-3-methylcyclohexane.
1
views
Textbook Question
From the nine stereoisomers, identify one pair of enantiomers.
1
views