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

4. Alkanes and Cycloalkanes

Cis vs Trans

Organic Chemistry

4. Alkanes and Cycloalkanes

Cis vs Trans

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2:02 minutes

Problem 70f

Textbook Question

Do the following compounds have the E or the Z configuration?
f.

Verified step by step guidance

Step 1: Understand the E/Z nomenclature. The E/Z system is used to describe the stereochemistry of double bonds. 'E' stands for 'entgegen' (opposite), meaning the highest priority groups are on opposite sides of the double bond. 'Z' stands for 'zusammen' (together), meaning the highest priority groups are on the same side of the double bond.

Step 2: Assign priorities to the substituents on each carbon of the double bond using the Cahn-Ingold-Prelog priority rules. These rules state that the atom with the higher atomic number directly attached to the double bond gets higher priority. If the atoms are the same, move outward to the next set of atoms until a difference is found.

Step 3: Determine the spatial arrangement of the highest priority groups. Look at the double bond and identify whether the highest priority groups are on the same side (Z configuration) or on opposite sides (E configuration).

Step 4: If the problem provides specific compounds, analyze the substituents attached to the double bond in each compound. Apply the priority rules to each substituent and compare their positions relative to the double bond.

Step 5: Once the priorities and spatial arrangement are determined, assign the configuration (E or Z) to each compound based on the positions of the highest priority groups.

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Key Concepts

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

E/Z Configuration

E/Z configuration is a method of describing the stereochemistry of alkenes based on the priority of substituents attached to the double bond. The 'E' (entgegen) configuration indicates that the highest priority groups are on opposite sides, while the 'Z' (zusammen) configuration indicates they are on the same side. This system is crucial for understanding the geometric isomerism in alkenes.

Cahn-Ingold-Prelog Priority Rules

The Cahn-Ingold-Prelog priority rules are used to assign priority to substituents based on atomic number and connectivity. The atom with the higher atomic number receives higher priority. If the first atoms are the same, the priority is determined by the next atoms in the substituent chain, which is essential for determining E/Z configurations.

Geometric Isomerism

Geometric isomerism occurs when compounds have the same molecular formula and connectivity but differ in the spatial arrangement of atoms. In alkenes, this is primarily due to the restricted rotation around the double bond, leading to distinct E and Z isomers. Understanding this concept is vital for predicting the physical and chemical properties of the compounds.

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