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

Constitutional Isomers vs. Stereoisomers

Organic Chemistry

5. Chirality

Constitutional Isomers vs. Stereoisomers

Previous problemNext problem

Problem 11b

Textbook Question

For each of the following molecules, identify all stereocenters and draw all possible stereoisomers.
(b)

Verified step by step guidance

Step 1: Analyze the molecular structure provided. The molecule contains a bromine atom attached to a carbon, along with a triple bond and other substituents. Identify any stereocenters by looking for carbons bonded to four different groups.

Step 2: Determine if the molecule contains stereocenters. A stereocenter is a carbon atom that is bonded to four distinct groups. In this molecule, the carbon attached to the bromine atom is a stereocenter because it is bonded to a bromine, a methyl group, an ethyl group, and the rest of the molecule.

Step 3: Consider the triple bond. Triple bonds do not exhibit cis-trans isomerism because the linear geometry of the bond does not allow for restricted rotation. Therefore, the triple bond does not contribute to stereoisomerism.

Step 4: Calculate the number of possible stereoisomers. For each stereocenter, there are two possible configurations (R and S). Since there is one stereocenter in this molecule, there are 2^1 = 2 possible stereoisomers.

Step 5: Draw the stereoisomers. Represent the molecule with the bromine atom in both R and S configurations. Use wedge and dash bonds to indicate the spatial arrangement of the substituents around the stereocenter.

Verified video answer for a similar problem:

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

Play a video:

Was this helpful?

Key Concepts

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

Stereocenters

Stereocenters, or chiral centers, are atoms in a molecule that have four different substituents attached to them, leading to non-superimposable mirror images. In organic chemistry, these centers are crucial for determining the molecule's chirality, which affects its optical activity and interactions with other chiral substances.

Stereoisomers

Stereoisomers are compounds that have the same molecular formula and connectivity of atoms but differ in the spatial arrangement of their atoms. This category includes enantiomers, which are mirror images of each other, and diastereomers, which are not mirror images. The number of stereoisomers can be calculated using the formula 2^n, where n is the number of stereocenters.

Drawing Stereoisomers

Drawing stereoisomers involves representing the three-dimensional arrangement of atoms in a two-dimensional format. Techniques such as wedge-and-dash notation help illustrate the spatial orientation of substituents around stereocenters. Understanding how to visualize and draw these structures is essential for identifying all possible stereoisomers of a given molecule.

Watch next

Master Determining when molecules are different. with a bite sized video explanation from Johnny

Start learning

Related Videos

Related Practice

Textbook Question

For the molecules shown,

(i) count the number of stereocenters present and

(ii) draw all possible stereoisomers.

(iii) Identify the relationships between stereoisomers as enantiomers or diastereomers.

(c)

Textbook Question

Which of the following compounds are capable of being resolved into enantiomers?

(a) N-ethyl-N-methylaniline

(b) 2-methylpiperidine

Textbook Question

For each of the following molecules, identify all stereocenters and draw all possible stereoisomers.

(a)

Textbook Question

For each of the following molecules, identify all stereocenters and draw all possible stereoisomers.

(f)

Textbook Question

Draw a three-dimensional structure for each compound, and star all asymmetric carbon atoms. Draw the mirror image for each structure, and state whether you have drawn a pair of enantiomers or just the same molecule twice.Build molecular models of any of these examples that seem difficult to youe. Chlorocyclohexanef. Cis-1,2-dichlorocyclobutane

Textbook Question

Draw a three-dimensional structure for each compound, and star all asymmetric carbon atoms. Draw the mirror for each structure, and state whether you have drawn a pair of enantiomers or just the same molecule twice. Build molecular models of any of these examples that seem difficult to you.

(e) chlorocyclohexane

(f) cis-1,2-dichlorocyclobutane

Textbook Question

For each pair, give the relationship between the two compounds. Making models will be helpful.

(a) (2R,3S)-2,3-dibromohexane and (2S,3R)-2,3-dibromohexane

(b) (2R,3S)-2,3-dibromohexane and (2R,3R)-2,3-dibromohexane

Textbook Question

For the compound 1-ethyl-3-isopropylcyclopentane,

(b) What is the stereochemical relationship between the cis isomers?

Show more practices