Textbook Question
Suggest an alkene that could be used to make each of the following halohydrins.
(a)
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10. Addition Reactions
Halohydrin
4:51 minutesProblem 45d(iv)
Textbook Question
Predict the product(s) that would result when the alkenes are allowed to react under the following conditions: (iv) Cl2, CH3OH
(d) 
Verified step by step guidance1
Identify the type of reaction: The reaction involves an alkene reacting with Cl₂ in the presence of CH₃OH. This is an example of a halohydrin formation reaction, where the alkene undergoes an electrophilic addition reaction.
Understand the mechanism: The reaction begins with the alkene attacking a chlorine molecule (Cl₂), forming a cyclic chloronium ion intermediate. This intermediate is highly reactive and will be attacked by a nucleophile.
Determine the nucleophile: In this reaction, CH₃OH (methanol) acts as the nucleophile. Methanol will attack the more substituted carbon of the cyclic chloronium ion due to the stability of the resulting carbocation-like transition state.
Predict the product: The nucleophilic attack by CH₃OH will open the cyclic chloronium ion, resulting in the formation of a halohydrin. The product will have a chlorine atom on one carbon and a methoxy group (-OCH₃) on the adjacent carbon, with anti stereochemistry (opposite sides of the double bond plane).
Consider regioselectivity and stereochemistry: The addition of Cl and -OCH₃ will follow Markovnikov's rule, where the -OCH₃ group attaches to the more substituted carbon. Additionally, the anti stereochemistry arises due to the backside attack of the nucleophile on the cyclic intermediate.
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Video duration:
4mKey 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, typically involving alkenes. In this process, the double bond of the alkene acts as a nucleophile, attacking the electrophile, leading to the formation of a more stable product. Understanding this mechanism is crucial for predicting the products of reactions involving alkenes.
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Halogenation
Halogenation refers to the addition of halogen atoms (like Cl₂) to an alkene, resulting in the formation of vicinal dihalides. This reaction typically proceeds through a cyclic halonium ion intermediate, which influences the stereochemistry of the product. Recognizing the nature of halogenation helps in predicting the outcome when alkenes react with halogens in various solvents.
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Solvent Effects
The choice of solvent can significantly influence the outcome of a chemical reaction. In the case of Cl₂ in CH₃OH (methanol), the polar protic nature of methanol can stabilize certain intermediates and facilitate the formation of products through solvation. Understanding solvent effects is essential for predicting reaction pathways and product distributions in organic reactions.
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