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

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6:12 minutes

Problem 26j,k

Textbook Question

Write structural formulas for the following compounds (includes both old- and new-style names).
(j) vinylacetylene
(k) (S)-3-methyl-1-penten-4-yne

Verified step by step guidance

Step 1: Understand the structure of vinylacetylene. The name 'vinylacetylene' suggests a compound containing both a vinyl group (-CH=CH2) and an acetylene group (-C≡CH). These groups are connected to form a single molecule.

Step 2: Draw the structure of vinylacetylene. Place the vinyl group (-CH=CH2) on one end and the acetylene group (-C≡CH) on the other, ensuring they are directly connected by a single bond. The resulting structure is CH2=CH-C≡CH.

Step 3: For (S)-3-methyl-1-penten-4-yne, break down the name. The '1-penten-4-yne' indicates a five-carbon chain with a double bond at position 1 and a triple bond at position 4. The '3-methyl' indicates a methyl group (-CH3) attached to the third carbon. The '(S)' specifies the stereochemistry of the chiral center at carbon 3.

Step 4: Draw the carbon chain for 1-penten-4-yne. Start with a five-carbon chain, placing a double bond between carbons 1 and 2, and a triple bond between carbons 4 and 5. Add the methyl group (-CH3) to carbon 3.

Step 5: Assign the (S) configuration to the chiral center at carbon 3. Use the Cahn-Ingold-Prelog priority rules to determine the priorities of the groups attached to carbon 3. Arrange the groups in 3D space so that the lowest priority group is pointing away from you, and verify that the remaining groups follow a counterclockwise order for the (S) configuration.

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Key Concepts

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

Structural Formulas

Structural formulas represent the arrangement of atoms within a molecule, illustrating how atoms are bonded together. They provide insight into the molecular geometry and functional groups present, which are crucial for understanding the compound's reactivity and properties. Different styles, such as condensed or skeletal formulas, can be used to convey this information succinctly.

Nomenclature in Organic Chemistry

Nomenclature refers to the systematic naming of organic compounds based on established rules, such as those set by the International Union of Pure and Applied Chemistry (IUPAC). Understanding both old-style and new-style names is essential for accurately identifying compounds and their structures. For example, 'vinylacetylene' and '(S)-3-methyl-1-penten-4-yne' illustrate how stereochemistry and functional groups are incorporated into names.

Stereochemistry

Stereochemistry is the study of the spatial arrangement of atoms in molecules and how this affects their chemical behavior. It is particularly important in compounds with chiral centers, as in the case of (S)-3-methyl-1-penten-4-yne, where the 'S' designation indicates a specific three-dimensional arrangement. Understanding stereochemistry is crucial for predicting the reactivity and interactions of organic molecules.

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