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

SN2 Reaction

Organic Chemistry

7. Substitution Reactions

SN2 Reaction

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4:04 minutes

Problem 14d

Textbook Question

Predict the major products of the following substitutions.
d. CH₃CH₂CH₂I + NaCN →

Verified step by step guidance

Identify the type of substitution reaction: The reaction involves CH3CH2CH2I (1-iodopropane) and NaCN (sodium cyanide). This is a nucleophilic substitution reaction, specifically SN2, because the substrate is a primary alkyl halide, which favors the SN2 mechanism.

Understand the mechanism: In an SN2 reaction, the nucleophile (CN⁻ from NaCN) attacks the electrophilic carbon (the carbon attached to the iodine atom) from the opposite side of the leaving group (I⁻). This results in a single-step, concerted mechanism with inversion of configuration at the carbon center.

Determine the nucleophile and leaving group: The nucleophile is CN⁻, which is a strong nucleophile, and the leaving group is I⁻, which is a good leaving group due to its large size and ability to stabilize the negative charge.

Predict the product: The CN⁻ nucleophile will replace the iodine atom in the substrate, forming a new carbon-carbon bond. The product will be CH3CH2CH2CN (butanenitrile), where the cyanide group (-CN) is attached to the terminal carbon of the original alkyl halide.

Verify the reaction conditions: Ensure that the reaction is carried out in a polar aprotic solvent (e.g., DMSO or acetone) to favor the SN2 mechanism and avoid side reactions.

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Key Concepts

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

Nucleophilic Substitution

Nucleophilic substitution is a fundamental reaction in organic chemistry where a nucleophile replaces a leaving group in a molecule. In this case, NaCN acts as the nucleophile, attacking the carbon atom bonded to the iodine in CH3CH2CH2I. Understanding the mechanism, whether it follows an SN1 or SN2 pathway, is crucial for predicting the product.

Leaving Groups

A leaving group is an atom or group that can depart from the parent molecule during a chemical reaction. In this reaction, iodine (I) is the leaving group, and its ability to leave is influenced by its bond strength and stability as an ion. A good leaving group enhances the likelihood of a successful nucleophilic substitution.

Stereochemistry of Substitution Reactions

Stereochemistry refers to the spatial arrangement of atoms in molecules and how this affects their chemical behavior. In nucleophilic substitution reactions, the stereochemistry can change depending on whether the reaction proceeds via an SN1 or SN2 mechanism. This is important for predicting the configuration of the product, especially if the substrate is chiral.