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

12. Alcohols, Ethers, Epoxides and Thiols

Leaving Group Conversions Summary

Organic Chemistry

12. Alcohols, Ethers, Epoxides and Thiols

Leaving Group Conversions Summary

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Problem 32

Textbook Question

When SOCl₂ is used in place of HCl, only one product results. Why are these conditions better?

Verified step by step guidance

Identify the starting material and the reagent: The starting material is an alcohol, and the reagent is thionyl chloride (SOCl2) in the presence of a base (Et3N).

Understand the mechanism: SOCl2 converts alcohols to alkyl chlorides through a mechanism that involves the formation of an intermediate chlorosulfite ester, which then undergoes a nucleophilic substitution reaction.

Compare with HCl: When HCl is used, the reaction typically proceeds through an SN1 mechanism, which can lead to carbocation rearrangements and result in multiple products.

Explain the advantage of SOCl2: The use of SOCl2 avoids carbocation formation and rearrangement, leading to a single product through an SN2 mechanism, which is stereospecific and retains the configuration of the starting material.

Conclude why SOCl2 is better: SOCl2 provides a more controlled and predictable reaction pathway, resulting in a single, desired product without side reactions or rearrangements.

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Key Concepts

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

Thionyl Chloride (SOCl₂) Reactivity

Thionyl chloride is a reagent commonly used in organic synthesis for converting alcohols into alkyl chlorides. Its unique reactivity allows for the formation of a single product due to the mechanism involving the formation of a cyclic intermediate, which leads to a more controlled reaction pathway compared to other reagents like HCl.

Mechanism of Nucleophilic Substitution

Nucleophilic substitution is a fundamental reaction in organic chemistry where a nucleophile replaces a leaving group in a molecule. The mechanism can proceed via either an SN1 or SN2 pathway, influencing the number of products formed. SOCl₂ typically favors the SN2 mechanism, resulting in a single product due to its steric and electronic properties.

Selectivity in Organic Reactions

Selectivity refers to the ability of a reaction to produce a specific product over others. In the case of SOCl₂, the reaction conditions and the nature of the reagent lead to high selectivity, minimizing side reactions and by-products. This contrasts with HCl, which can lead to multiple products due to its less selective nature in nucleophilic substitution.