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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6:45 minutes

Problem 12b

Textbook Question

Draw the isomers for the following compounds and then name each one:
b. 2,4-heptadiene

Verified step by step guidance

Step 1: Understand the structure of 2,4-heptadiene. The name indicates a seven-carbon chain (hept-) with two double bonds located at positions 2 and 4. The suffix '-diene' specifies the presence of two double bonds.

Step 2: Begin by drawing the parent chain of seven carbons. Place double bonds at the 2nd and 4th positions. Ensure the numbering starts from the end of the chain that gives the lowest possible numbers to the double bonds.

Step 3: Consider the possibility of cis-trans (E/Z) isomerism for each double bond. Double bonds restrict rotation, so different spatial arrangements of substituents around the double bonds can lead to distinct isomers. For example, the 2nd double bond can be cis (Z) or trans (E), and the same applies to the 4th double bond.

Step 4: Draw all possible combinations of cis-trans isomers for the molecule. For instance, you can have (Z,Z), (E,E), (Z,E), and (E,Z) configurations for the two double bonds.

Step 5: Name each isomer using the E/Z nomenclature. Assign priorities to the substituents on each double bond based on the Cahn-Ingold-Prelog rules, and determine whether the substituents are on the same side (Z) or opposite sides (E) of the double bond. Combine this information with the base name '2,4-heptadiene' to fully name each isomer.

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Key Concepts

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

Isomerism

Isomerism refers to the phenomenon where two or more compounds have the same molecular formula but different structural arrangements or spatial orientations. In organic chemistry, isomers can be classified into structural isomers, which differ in the connectivity of atoms, and stereoisomers, which have the same connectivity but differ in the spatial arrangement of atoms. Understanding isomerism is crucial for drawing and naming compounds accurately.

Dienes

Dienes are organic compounds that contain two double bonds in their structure. They can be classified as conjugated, where the double bonds are separated by a single bond, or isolated, where the double bonds are separated by more than one single bond. In the case of 2,4-heptadiene, recognizing its diene nature is essential for identifying its isomers and understanding its reactivity and properties.

Nomenclature

Nomenclature in organic chemistry is the system of naming chemical compounds based on their structure and functional groups. The International Union of Pure and Applied Chemistry (IUPAC) provides rules for naming compounds, which include identifying the longest carbon chain, numbering the carbon atoms, and indicating the position of double bonds. Proper nomenclature is vital for clear communication and understanding of chemical structures, especially when dealing with isomers.

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