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

16. Conjugated Systems

Pericyclic Reaction

Organic Chemistry

16. Conjugated Systems

Pericyclic Reaction

Previous problemNext problem

Struggling with Organic Chemistry?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

Which of the following is NOT a pericyclic reaction?

The figure illustrates a reaction. The reaction contains two reactants and one product. The first reactant has the following structure: A 5-carbon pentagonal ring is in a horizontal orientation with C 1 occupying the leftmost vertex. A double bond is present between C 3 and C 4. The second reactant is O s O 4 written over the reaction arrow. The product has the following structure: A 5-carbon pentagonal ring is in a horizontal orientation with C 1 occupying the leftmost vertex. The ring is fused to a 5-membered heterocyclic pentagonal ring in a horizontal orientation consisting of 1 O s, 2 O, and 2 C atoms. In the 5-membered heterocyclic ring, the O s atom occupies the first position, which is the rightmost vertex, the first O atom occupies the second position, which is the bottom right vertex, and the second O atom occupies the fifth position, which is the top right vertex. The two rings are fused to each other such that C 3 and C 4 of the 5-carbon ring are the C 2 and C 1 of the 5-membered heterocyclic ring, respectively. O s is double bonded to a third O atom on the upper right and a fourth O atom on the lower right.

The figure illustrates a reaction. The reaction contains two reactants and one product. The first reactant has the following structure: A 4-carbon alkene chain is depicted as a line structure using 3 zigzag lines. A double bond is present between C 1 and C 2 and C 3 and C 4. The second reactant has the following structure: A 2-carbon alkene chain is depicted as a line structure using 2 parallel lines. Delta is written under the reaction arrow. The product has the following structure: A 6-carbon hexagonal ring is in a vertical orientation with C 1 occupying the topmost vertex. A double bond is present between C 5 and C 6.

Previous problemNext problem

Verified step by step guidance

Identify the characteristics of a pericyclic reaction. Pericyclic reactions are concerted processes that occur through a cyclic transition state and involve the redistribution of bonding electrons. Common types include cycloadditions, electrocyclic reactions, and sigmatropic rearrangements.

Analyze the first reaction: the addition of OsO4 to a double bond. This is an example of a dihydroxylation reaction, which is not a pericyclic reaction. It involves the formation of a cyclic osmate ester intermediate, but it is not concerted in the sense of pericyclic reactions.

Examine the second reaction: the Diels-Alder reaction. This is a classic example of a pericyclic reaction, specifically a [4+2] cycloaddition, where a diene and a dienophile form a six-membered ring through a concerted mechanism.

Consider the third reaction: the addition of HCl to an alkene. This is an electrophilic addition reaction, not a pericyclic reaction. It involves the formation of a carbocation intermediate and is not concerted.

Review the fourth reaction: ozonolysis of an alkene. This reaction involves the formation of an ozonide intermediate and is not a pericyclic reaction. It is a stepwise process involving multiple steps, including the formation and cleavage of the ozonide.