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

10. Addition Reactions

Epoxide Reactions

Organic Chemistry

10. Addition Reactions

Epoxide Reactions

Previous problemNext problem

5:32 minutes

Problem 36a

Textbook Question

The existence of the NIH shift was established by determining the major product obtained from rearrangement of the following arene oxide, in which a hydrogen has been replaced by a deuterium.
a. What would be the major product if the NIH shift occurs? (Hint: A C—H bond is easier to break than a C—D bond.)

Verified step by step guidance

Step 1: Analyze the structure of the arene oxide provided in the image. The molecule contains a deuterium (D) atom and a hydrogen (H) atom attached to the same carbon adjacent to the epoxide group. The epoxide group is highly reactive and prone to rearrangement under acidic conditions (HB⁺).

Step 2: Understand the NIH shift mechanism. The NIH shift involves the migration of a hydrogen (or deuterium) atom during the rearrangement of the arene oxide. This occurs due to the breaking of the C-H or C-D bond and subsequent reattachment to a neighboring carbon atom.

Step 3: Consider the bond strength of C-H versus C-D. The C-H bond is easier to break than the C-D bond because the C-D bond is stronger due to the heavier mass of deuterium. This means the hydrogen atom is more likely to migrate during the NIH shift.

Step 4: Predict the rearrangement product. During the NIH shift, the hydrogen atom (H) migrates to the neighboring carbon atom, while the deuterium (D) remains in its original position. This results in the formation of a rearranged product where the hydrogen is now attached to a different carbon.

Step 5: Verify the major product. The major product will have the hydrogen atom relocated to the neighboring carbon, while the deuterium remains unchanged. This rearrangement stabilizes the molecule and completes the NIH shift process.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

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

NIH Shift

The NIH shift refers to a specific rearrangement mechanism in organic chemistry where a hydrogen atom is replaced by a deuterium atom during the reaction. This shift is significant in understanding the behavior of arene oxides, as it illustrates how the stability of intermediates can influence the final product. The NIH shift is particularly relevant when considering the bond strengths of C—H versus C—D bonds, as the latter is generally stronger.

Arene Oxides

Arene oxides are reactive intermediates formed from the oxidation of aromatic compounds. They are characterized by an epoxide-like structure where an oxygen atom is bonded to a carbon atom in the aromatic ring. Understanding the reactivity of arene oxides is crucial for predicting the outcomes of various organic reactions, including rearrangements like the NIH shift, as they can lead to different products based on the stability of the resulting structures.

Isotope Effects

Isotope effects refer to the differences in reaction rates or mechanisms that occur when isotopes of an element are substituted in a molecule. In this context, the presence of deuterium (D) instead of hydrogen (H) affects the bond strength, making C—D bonds stronger and less likely to break compared to C—H bonds. This concept is essential for predicting the major product of the NIH shift, as it influences which bond will break during the rearrangement process.

Watch next

Master Acid-Catalyzed Epoxide Ring-Opening with a bite sized video explanation from Johnny

Start learning