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

7. Substitution Reactions

Substitution Comparison

Organic Chemistry

7. Substitution Reactions

Substitution Comparison

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3:51 minutes

Problem 11c

Textbook Question

What stereoisomers do the following reactions form?
c.

Verified step by step guidance

Step 1: Analyze the starting material. The given compound is a cyclobutane ring with an alcohol (-OH) group attached to one of the carbons. The stereochemistry of the alcohol group is shown as a wedge, indicating it is above the plane of the ring.

Step 2: Examine the first reaction step. Thionyl chloride (SOCl₂) in the presence of pyridine is used to convert the alcohol group into a chloride (-Cl) group. This reaction proceeds via an SN2 mechanism, which inverts the stereochemistry of the substituent. Therefore, the chloride group will be below the plane of the ring (dash).

Step 3: Consider the second reaction step. Ethoxide ion (C₂H₅O⁻) acts as a nucleophile and performs an SN2 substitution on the alkyl chloride. Since SN2 reactions also invert stereochemistry, the ethoxy group (-OCH₂CH₃) will replace the chloride and end up above the plane of the ring (wedge).

Step 4: Determine the stereoisomer formed. The final product will have the ethoxy group (-OCH₂CH₃) above the plane of the cyclobutane ring, maintaining the stereochemical inversion from the first step and the second step.

Step 5: Summarize the stereochemical outcome. The reaction sequence results in a stereoisomer where the ethoxy group is in the same stereochemical position as the original alcohol group (above the plane of the ring), due to two consecutive inversions of stereochemistry.

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Key Concepts

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

Stereoisomerism

Stereoisomerism refers to the phenomenon where compounds have the same molecular formula and connectivity of atoms but differ in the spatial arrangement of their atoms. This can lead to different physical and chemical properties. The two main types of stereoisomers are enantiomers, which are non-superimposable mirror images, and diastereomers, which are not mirror images of each other.

Substitution Reactions

Substitution reactions involve the replacement of one functional group in a molecule with another. In the context of the provided reaction, thionyl chloride (SOCl2) is used to convert an alcohol into a better leaving group, facilitating the substitution by the nucleophile (C2H5O−). Understanding the mechanism of these reactions is crucial for predicting the stereochemical outcomes.

Nucleophilic Attack and Stereochemistry

In nucleophilic substitution reactions, the nucleophile attacks the electrophilic carbon, leading to the formation of new bonds. The stereochemistry of the product depends on whether the reaction proceeds via an SN1 or SN2 mechanism. SN2 reactions are characterized by a backside attack, resulting in inversion of configuration, while SN1 reactions can lead to racemization due to the formation of a planar carbocation intermediate.

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