Hey guys. In this video, I'm going to go over a specific type of sigmatropic shift that's called a Cope rearrangement. So what is the Cope rearrangement? Well, it's a heat-activated [3,3] sigmatropic shift that involves only hydrocarbons. Okay? So it's a specific type of [3,3] sigmatropic shift that involves only hydrocarbons, meaning you can't have oxygen involved, no heteroatoms, and I just want to remind you that this means that all the rules of pericyclic reactions still apply. This is concerted, it's non-ionic, it's reversible, all of that. But on top of that, it just happens to be a very specific subset of sigma tropic shifts, okay? Now, depending on how many pericyclic reactions you've had to learn at this point, you might have a lot of different actions in your head. It really depends on how much your professor is putting on you right now, if they want you to just know Cope or if they want you to know a bunch of them. But I'm here to tell you that it's actually very easy to distinguish the Cope rearrangement from a lot of other different types of pericyclic reactions because this is one of the few that happens without any conjugation at all. Notice that my first molecule, the thing that I'm starting with, is not conjugated. This is not a typical diene. This is, I mean, it's a diene, but it's an isolated diene. It's not a conjugated diene. So when you see this type of rearrangement happening and it doesn't have a conjugated beginning point, the beginning point is not conjugated, and it's hydrocarbons, you know that it's a Cope rearrangement. So I'm just trying to give you some clarity on how to think about recognizing this. Also, just so you guys know, this molecule, the starting reactant, may require some rotation to visualize the [3,3] location, meaning that right now I have it very conveniently aligned for you so that it's very easy to visualize but sometimes your homework or your professor could give it to you in a way that's like linear, and you're going to have to kind of rotate it yourself to visualize what the resulting mechanism would look like. Okay. Cool. So why is it called a [3,3]? Let's just go over this one more time. We have a bond breaking here between the ones. We have a bond that's being formed between the threes. So if you count it around, that means that you're forming a new bond between the [3,3]. Once again, this is hydrocarbons only, so it's called a Cope rearrangement. Also, I just want to remind you guys of the mechanism. The mechanism would just be something, there are multiple ways you could draw it but just something that makes sense where you're breaking a bond and you're making a new bond. So what I would draw is something like this. Awesome. So that being said, let’s go ahead and do this example. So provide the mechanism and final product for the following reaction. So notice here, guys, that I'm given an isolated diene that's only hydrocarbons, but it's not lined up in a way that's easy for me to react because it's written out in a linear structure. So, like I said before, I can even decide what this is, let's try rotating it so they can face each other and so we can get a better idea of what we're looking at. So what I’m going to try to do, here and maybe in this space right here, is I’m going to redraw the molecule in such a way so that I can see what it looks like. So let's go ahead and draw it. This can just be a circle. Actually, let's just draw it anyway. Cool. And then what I'm going to draw is I’m going to draw this double bond facing the same direction but then everything else wrapping underneath it. So I’m going to put this single bond here. Now instead of the next double bond going up I’m going to draw it down. Instead of the next one going like off to the left, off to the right I’m going to put it to the left and then there appears to be one more double bond that I can face this way. Cool, and now I have something that I can look at, in fact, I drew it too small. I mean, I can work with it but let’s make it a little bigger so it’s easier to look at. Cool. Awesome. So now that we have this molecule that's rotated correctly, we can think, is this like what type of reaction is this? Well, it’s not conjugated. It's an isolated diene, so there are really no other pericyclic reactions that could happen here. It has to be a sigmatropic shift. And specifically, it’s, there are only hydrocarbons involved so this looks like it’s going to be a Cope rearrangement which is a [3,3]. So let’s go ahead and, draw the mechanism and then provide the product. So the mechanism would be that I break the bond and make a new double bond, then this double bond comes and I make a new single bond and then this one comes around as well. So what this is going to give me is a new compound that looks like this where now at the bottom what I have is a double bond here, a single bond here, a single bond here, and a double bond here. Cool? Just so you know, the final product here is actually the same exact product that we started with, okay? Because the fact this is a very it happened to be a very simple Cope arrangement where there were not a lot of substituents, so the end product turned out to be the same exact thing that we started off with. That’s totally fine, that happens with sigma tropic shifts sometimes. So just you know, just so you are aware, if you ever get the same product, be sure to be careful but it’s okay. That happens with sigma tropic shifts times. Okay? So that is our product and once again we already know it's a Cope rearrangement, but if we had to name it, the way we would name it is by counting this is the 1, this is the 2, and this is the 3, and then realizing this is going to be a [3,3] Cope rearrangement. Awesome. So that's it for this concept and example. Let’s see if you guys can do the practice problem yourselves.
Table of contents
- 1. A Review of General Chemistry5h 9m
- Summary23m
- Intro to Organic Chemistry5m
- Atomic Structure16m
- Wave Function9m
- Molecular Orbitals17m
- Sigma and Pi Bonds9m
- Octet Rule12m
- Bonding Preferences12m
- Formal Charges6m
- Skeletal Structure14m
- Lewis Structure20m
- Condensed Structural Formula15m
- Degrees of Unsaturation15m
- Constitutional Isomers14m
- Resonance Structures46m
- Hybridization28m
- Molecular Geometry16m
- Electronegativity22m
- 2. Molecular Representations1h 14m
- 3. Acids and Bases2h 46m
- 4. Alkanes and Cycloalkanes4h 19m
- IUPAC Naming29m
- Alkyl Groups13m
- Naming Cycloalkanes10m
- Naming Bicyclic Compounds10m
- Naming Alkyl Halides7m
- Naming Alkenes3m
- Naming Alcohols8m
- Naming Amines15m
- Cis vs Trans21m
- Conformational Isomers13m
- Newman Projections14m
- Drawing Newman Projections16m
- Barrier To Rotation7m
- Ring Strain8m
- Axial vs Equatorial7m
- Cis vs Trans Conformations4m
- Equatorial Preference14m
- Chair Flip9m
- Calculating Energy Difference Between Chair Conformations17m
- A-Values17m
- Decalin7m
- 5. Chirality3h 39m
- Constitutional Isomers vs. Stereoisomers9m
- Chirality12m
- Test 1:Plane of Symmetry7m
- Test 2:Stereocenter Test17m
- R and S Configuration43m
- Enantiomers vs. Diastereomers13m
- Atropisomers9m
- Meso Compound12m
- Test 3:Disubstituted Cycloalkanes13m
- What is the Relationship Between Isomers?16m
- Fischer Projection10m
- R and S of Fischer Projections7m
- Optical Activity5m
- Enantiomeric Excess20m
- Calculations with Enantiomeric Percentages11m
- Non-Carbon Chiral Centers8m
- 6. Thermodynamics and Kinetics1h 22m
- 7. Substitution Reactions1h 48m
- 8. Elimination Reactions2h 30m
- 9. Alkenes and Alkynes2h 9m
- 10. Addition Reactions3h 18m
- Addition Reaction6m
- Markovnikov5m
- Hydrohalogenation6m
- Acid-Catalyzed Hydration17m
- Oxymercuration15m
- Hydroboration26m
- Hydrogenation6m
- Halogenation6m
- Halohydrin12m
- Carbene12m
- Epoxidation8m
- Epoxide Reactions9m
- Dihydroxylation8m
- Ozonolysis7m
- Ozonolysis Full Mechanism24m
- Oxidative Cleavage3m
- Alkyne Oxidative Cleavage6m
- Alkyne Hydrohalogenation3m
- Alkyne Halogenation2m
- Alkyne Hydration6m
- Alkyne Hydroboration2m
- 11. Radical Reactions1h 58m
- 12. Alcohols, Ethers, Epoxides and Thiols2h 42m
- Alcohol Nomenclature4m
- Naming Ethers6m
- Naming Epoxides18m
- Naming Thiols11m
- Alcohol Synthesis7m
- Leaving Group Conversions - Using HX11m
- Leaving Group Conversions - SOCl2 and PBr313m
- Leaving Group Conversions - Sulfonyl Chlorides7m
- Leaving Group Conversions Summary4m
- Williamson Ether Synthesis3m
- Making Ethers - Alkoxymercuration4m
- Making Ethers - Alcohol Condensation4m
- Making Ethers - Acid-Catalyzed Alkoxylation4m
- Making Ethers - Cumulative Practice10m
- Ether Cleavage8m
- Alcohol Protecting Groups3m
- t-Butyl Ether Protecting Groups5m
- Silyl Ether Protecting Groups10m
- Sharpless Epoxidation9m
- Thiol Reactions6m
- Sulfide Oxidation4m
- 13. Alcohols and Carbonyl Compounds2h 17m
- 14. Synthetic Techniques1h 26m
- 15. Analytical Techniques:IR, NMR, Mass Spect6h 50m
- Purpose of Analytical Techniques5m
- Infrared Spectroscopy16m
- Infrared Spectroscopy Table31m
- IR Spect:Drawing Spectra40m
- IR Spect:Extra Practice26m
- NMR Spectroscopy10m
- 1H NMR:Number of Signals26m
- 1H NMR:Q-Test26m
- 1H NMR:E/Z Diastereoisomerism8m
- H NMR Table21m
- 1H NMR:Spin-Splitting (N + 1) Rule17m
- 1H NMR:Spin-Splitting Simple Tree Diagrams11m
- 1H NMR:Spin-Splitting Complex Tree Diagrams8m
- 1H NMR:Spin-Splitting Patterns8m
- NMR Integration18m
- NMR Practice14m
- Carbon NMR4m
- Structure Determination without Mass Spect47m
- Mass Spectrometry12m
- Mass Spect:Fragmentation28m
- Mass Spect:Isotopes27m
- 16. Conjugated Systems6h 13m
- Conjugation Chemistry13m
- Stability of Conjugated Intermediates4m
- Allylic Halogenation12m
- Reactions at the Allylic Position39m
- Conjugated Hydrohalogenation (1,2 vs 1,4 addition)26m
- Diels-Alder Reaction9m
- Diels-Alder Forming Bridged Products11m
- Diels-Alder Retrosynthesis8m
- Molecular Orbital Theory9m
- Drawing Atomic Orbitals6m
- Drawing Molecular Orbitals17m
- HOMO LUMO4m
- Orbital Diagram:3-atoms- Allylic Ions13m
- Orbital Diagram:4-atoms- 1,3-butadiene11m
- Orbital Diagram:5-atoms- Allylic Ions10m
- Orbital Diagram:6-atoms- 1,3,5-hexatriene13m
- Orbital Diagram:Excited States4m
- Pericyclic Reaction10m
- Thermal Cycloaddition Reactions26m
- Photochemical Cycloaddition Reactions26m
- Thermal Electrocyclic Reactions14m
- Photochemical Electrocyclic Reactions10m
- Cumulative Electrocyclic Problems25m
- Sigmatropic Rearrangement17m
- Cope Rearrangement9m
- Claisen Rearrangement15m
- 17. Ultraviolet Spectroscopy51m
- 18. Aromaticity2h 31m
- 19. Reactions of Aromatics: EAS and Beyond5h 1m
- Electrophilic Aromatic Substitution9m
- Benzene Reactions11m
- EAS:Halogenation Mechanism6m
- EAS:Nitration Mechanism9m
- EAS:Friedel-Crafts Alkylation Mechanism6m
- EAS:Friedel-Crafts Acylation Mechanism5m
- EAS:Any Carbocation Mechanism7m
- Electron Withdrawing Groups22m
- EAS:Ortho vs. Para Positions4m
- Acylation of Aniline9m
- Limitations of Friedel-Crafts Alkyation19m
- Advantages of Friedel-Crafts Acylation6m
- Blocking Groups - Sulfonic Acid12m
- EAS:Synergistic and Competitive Groups13m
- Side-Chain Halogenation6m
- Side-Chain Oxidation4m
- Reactions at Benzylic Positions31m
- Birch Reduction10m
- EAS:Sequence Groups4m
- EAS:Retrosynthesis29m
- Diazo Replacement Reactions6m
- Diazo Sequence Groups5m
- Diazo Retrosynthesis13m
- Nucleophilic Aromatic Substitution28m
- Benzyne16m
- 20. Phenols55m
- 21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
- Naming Aldehydes8m
- Naming Ketones7m
- Oxidizing and Reducing Agents9m
- Oxidation of Alcohols28m
- Ozonolysis7m
- DIBAL5m
- Alkyne Hydration9m
- Nucleophilic Addition8m
- Cyanohydrin11m
- Organometallics on Ketones19m
- Overview of Nucleophilic Addition of Solvents13m
- Hydrates6m
- Hemiacetal9m
- Acetal12m
- Acetal Protecting Group16m
- Thioacetal6m
- Imine vs Enamine15m
- Addition of Amine Derivatives5m
- Wolff Kishner Reduction7m
- Baeyer-Villiger Oxidation39m
- Acid Chloride to Ketone7m
- Nitrile to Ketone9m
- Wittig Reaction18m
- Ketone and Aldehyde Synthesis Reactions14m
- 22. Carboxylic Acid Derivatives: NAS2h 51m
- Carboxylic Acid Derivatives7m
- Naming Carboxylic Acids9m
- Diacid Nomenclature6m
- Naming Esters5m
- Naming Nitriles3m
- Acid Chloride Nomenclature5m
- Naming Anhydrides7m
- Naming Amides5m
- Nucleophilic Acyl Substitution18m
- Carboxylic Acid to Acid Chloride6m
- Fischer Esterification5m
- Acid-Catalyzed Ester Hydrolysis4m
- Saponification3m
- Transesterification5m
- Lactones, Lactams and Cyclization Reactions10m
- Carboxylation5m
- Decarboxylation Mechanism14m
- Review of Nitriles46m
- 23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
- 24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
- Tautomerization9m
- Tautomers of Dicarbonyl Compounds6m
- Enolate4m
- Acid-Catalyzed Alpha-Halogentation4m
- Base-Catalyzed Alpha-Halogentation3m
- Haloform Reaction8m
- Hell-Volhard-Zelinski Reaction3m
- Overview of Alpha-Alkylations and Acylations5m
- Enolate Alkylation and Acylation12m
- Enamine Alkylation and Acylation16m
- Beta-Dicarbonyl Synthesis Pathway7m
- Acetoacetic Ester Synthesis13m
- Malonic Ester Synthesis15m
- 25. Condensation Chemistry2h 9m
- 26. Amines1h 43m
- 27. Heterocycles2h 0m
- Nomenclature of Heterocycles15m
- Acid-Base Properties of Nitrogen Heterocycles10m
- Reactions of Pyrrole, Furan, and Thiophene13m
- Directing Effects in Substituted Pyrroles, Furans, and Thiophenes16m
- Addition Reactions of Furan8m
- EAS Reactions of Pyridine17m
- SNAr Reactions of Pyridine18m
- Side-Chain Reactions of Substituted Pyridines20m
- 28. Carbohydrates5h 53m
- Monosaccharide20m
- Monosaccharides - D and L Isomerism9m
- Monosaccharides - Drawing Fischer Projections18m
- Monosaccharides - Common Structures6m
- Monosaccharides - Forming Cyclic Hemiacetals12m
- Monosaccharides - Cyclization18m
- Monosaccharides - Haworth Projections13m
- Mutarotation11m
- Epimerization9m
- Monosaccharides - Aldose-Ketose Rearrangement8m
- Monosaccharides - Alkylation10m
- Monosaccharides - Acylation7m
- Glycoside6m
- Monosaccharides - N-Glycosides18m
- Monosaccharides - Reduction (Alditols)12m
- Monosaccharides - Weak Oxidation (Aldonic Acid)7m
- Reducing Sugars23m
- Monosaccharides - Strong Oxidation (Aldaric Acid)11m
- Monosaccharides - Oxidative Cleavage27m
- Monosaccharides - Osazones10m
- Monosaccharides - Kiliani-Fischer23m
- Monosaccharides - Wohl Degradation12m
- Monosaccharides - Ruff Degradation12m
- Disaccharide30m
- Polysaccharide11m
- 29. Amino Acids3h 20m
- Proteins and Amino Acids19m
- L and D Amino Acids14m
- Polar Amino Acids14m
- Amino Acid Chart18m
- Acid-Base Properties of Amino Acids33m
- Isoelectric Point14m
- Amino Acid Synthesis: HVZ Method12m
- Synthesis of Amino Acids: Acetamidomalonic Ester Synthesis16m
- Synthesis of Amino Acids: N-Phthalimidomalonic Ester Synthesis13m
- Synthesis of Amino Acids: Strecker Synthesis13m
- Reactions of Amino Acids: Esterification7m
- Reactions of Amino Acids: Acylation3m
- Reactions of Amino Acids: Hydrogenolysis6m
- Reactions of Amino Acids: Nihydrin Test11m
- 32. Lipids 2h 50m
- 34. Nucleic Acids1h 32m
- 35. Transition Metals5h 33m
- Electron Configuration of Elements45m
- Coordination Complexes20m
- Ligands24m
- Electron Counting10m
- The 18 and 16 Electron Rule13m
- Cross-Coupling General Reactions40m
- Heck Reaction40m
- Stille Reaction13m
- Suzuki Reaction25m
- Sonogashira Coupling Reaction17m
- Fukuyama Coupling Reaction15m
- Kumada Coupling Reaction13m
- Negishi Coupling Reaction16m
- Buchwald-Hartwig Amination Reaction19m
- Eglinton Reaction17m
16. Conjugated Systems
Cope Rearrangement
16. Conjugated Systems
Cope Rearrangement - Online Tutor, Practice Problems & Exam Prep
Created using AI
Ready to learn a specific type of sigmatropic shift? The cope rearrangement can be differentiated from other pericyclic reactions due to its lack of conjugation.
1
concept
Definition of Cope Rearrangement
Video duration:
6mPlay a video:
Video transcript
2
Problem
ProblemProvide the mechanism and final product for the following reaction
A
B
C
D
Do you want more practice?
More setsYour Organic Chemistry tutors
Additional resources for Cope Rearrangement
PRACTICE PROBLEMS AND ACTIVITIES (4)
- (•) Predict the product of the Cope reactions shown. (a)
- (•) Predict the product of the Cope reactions shown. (c)
- Predict the product of the following sigmatropic rearrangements. Be sure to rationalize the stereochemical out...
- Predict the product of the following sigmatropic rearrangements. Be sure to rationalize the stereochemical out...