a. What is the major product obtained from the reaction of propene and Br 2 plus excess Cl - ? b. Indicate the relative amounts of the stereoisomers that are obtained.

Hello everyone. Today, we have the following problem. What is the major product of the reaction between one butane and molecular bromine in the presence of excess chloride ions also specify the relative amounts of any stereo isomers produced. So this is an example of a alkene Hagen nation which involves forming an anti vonda Halide if we draw one butane, that is a four carbon structure with an alkene on a carbon one. And upon reacting with molecular bromine as the nuclear file approaches the bromine, there will be a nucleic attack on the bromine, but then there will be a reciprocal nucleic attack of the same bromine on the other carbon of the alkene displacing the second bromine. And this will form a three member braum ion. Now what occurs next is the chloride that is in excess will form a nucleic attack on which carbon, well, it will occur on the more substituted carbon or the carbon that has the ethyl group. And that is due to the fact that that carbon bears more of the positive charge and is better able to stabilize that positive charge due to the hyper conjugation of that alkyl group. And thus, is more electrophysi can attack via front side attack or a backside attack. If it does so via a front side attack, it will result in the following product. And if it results via a backside attack, it will result in the following problem. And so in reference or with the with the relative amounts of the sterile isomers, they will be produced in equal amounts. And so with that, we have solved the problem overall, I hope this helped. And until next time.

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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

Halogenation

Organic Chemistry

10. Addition Reactions

Halogenation

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Problem 50

Textbook Question

a. What is the major product obtained from the reaction of propene and Br₂ plus excess Cl^-?
b. Indicate the relative amounts of the stereoisomers that are obtained.

Verified step by step guidance

Analyze the reaction: Propene (CH3-CH=CH2) reacts with Br2 in the presence of excess Cl-. This is an electrophilic addition reaction where the double bond in propene will react with Br2, forming a bromonium ion intermediate.

Step 1: The π-electrons of the double bond in propene attack one of the bromine atoms in Br2, leading to the formation of a bromonium ion intermediate. This intermediate is a three-membered ring with a positive charge on the bromine atom.

Step 2: The excess Cl- ions in the solution act as a nucleophile and attack the more substituted carbon of the bromonium ion (due to Markovnikov's rule and steric hindrance). This results in the opening of the bromonium ion ring and the formation of a vicinal (1,2-) halide product.

Step 3: Consider the stereochemistry of the product. The attack by Cl- occurs from the opposite side of the bromonium ion (anti-addition), leading to the formation of two stereoisomers: one with the bromine and chlorine atoms on opposite sides of the plane (trans) and one with them on the same side (cis).

Step 4: Indicate the relative amounts of stereoisomers. Due to the anti-addition mechanism, the trans stereoisomer is typically favored over the cis stereoisomer. The relative amounts depend on the reaction conditions, but the trans product is generally the major product.

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Key Concepts

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

Electrophilic Addition

Electrophilic addition is a fundamental reaction mechanism in organic chemistry where an electrophile reacts with a nucleophile, leading to the formation of a more saturated product. In the case of propene reacting with Br2, the double bond acts as a nucleophile, attacking the electrophilic bromine molecule, resulting in the formation of a bromonium ion intermediate.

Stereochemistry

Stereochemistry refers to the study of the spatial arrangement of atoms in molecules and how this affects their chemical behavior. When propene reacts with Br2, the formation of stereoisomers occurs due to the different spatial orientations of the substituents around the newly formed carbon-carbon bond, leading to products that can exhibit cis/trans or E/Z configurations.

Nucleophilic Substitution

Nucleophilic substitution is a reaction where a nucleophile replaces a leaving group in a molecule. In this scenario, the excess Cl- acts as a nucleophile that can attack the bromonium ion formed during the reaction, leading to the substitution of bromine with chlorine, which influences the final product distribution and the relative amounts of stereoisomers.

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