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

35. Transition Metals

Catalytic Allylic Alkylation

Organic Chemistry

35. Transition Metals

Catalytic Allylic Alkylation

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Multiple Choice

Beginning from 1-pentyne, synthesize the following compound via a catalytic allylic alkylation reaction.

Reaction scheme showing Na/NH3 and Pd(PPh3)4 for synthesizing a compound from 1-pentyne.

Reaction scheme with Na/NH3, Pd(PPh3)4, and Br2/hv for synthesizing a compound from 1-pentyne.

Reaction scheme with Na/NH3, Br2/hv, and Pd(PPh3)4 for synthesizing a compound from 1-pentyne.

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Verified step by step guidance

Start with 1-pentyne, which is an alkyne with five carbon atoms. The first step involves the partial reduction of the alkyne to a trans-alkene using sodium in liquid ammonia (Na/NH₃). This is known as the Birch reduction.

Next, perform a radical bromination using bromine (Br₂) and light (hv). This step introduces a bromine atom at the allylic position of the newly formed alkene, creating an allylic bromide.

Now, use palladium tetrakis(triphenylphosphine) (Pd(PPh₃)₄) as a catalyst to facilitate the allylic alkylation reaction. This involves the substitution of the bromine atom with a nucleophile, which in this case is the enolate ion derived from the diketone shown in the image.

The enolate ion is generated from the diketone, which has two carbonyl groups. The enolate formation involves the deprotonation of the alpha hydrogen between the two carbonyl groups, creating a resonance-stabilized anion.

Finally, the enolate ion attacks the allylic bromide, resulting in the formation of the desired compound with the new carbon-carbon bond. The stereochemistry of the product is determined by the configuration of the starting materials and the reaction conditions.