Textbook Question
What is the major product of each of the following reactions, assuming that one equivalent of each reagent is used in each reaction?
b.
10. Addition Reactions
Halogenation
Problem 45h(ii)
Textbook Question
Predict the product(s) that would result when the alkenes are allowed to react under the following conditions: (ii) Cl2
(h) 
Verified step by step guidance1
Identify the type of reaction: The reaction involves an alkene and Cl₂, which is a halogenation reaction. In this reaction, the π-bond of the alkene reacts with Cl₂ to form a vicinal dihalide (two halogen atoms added to adjacent carbons).
Understand the mechanism: The reaction proceeds via an electrophilic addition mechanism. The π-electrons of the alkene attack one of the chlorine atoms, forming a cyclic chloronium ion intermediate.
Determine the regioselectivity and stereochemistry: The cyclic chloronium ion intermediate is opened by the attack of the chloride ion (Cl⁻) on the more substituted carbon, if applicable. This results in anti-addition, meaning the two chlorine atoms will be added to opposite sides of the double bond.
Draw the product(s): Replace the double bond in the alkene with single bonds and add one chlorine atom to each of the two carbons that were part of the double bond. Ensure the stereochemistry reflects anti-addition (if stereocenters are formed).
Verify the product(s): Check the structure of the product(s) to ensure that the addition of Cl₂ follows the anti-addition pattern and that the correct number of chlorine atoms has been added to the molecule.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Was this helpful?
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, typically involving alkenes. In the case of alkenes reacting with Cl₂, the double bond acts as a nucleophile, attacking the chlorine molecule, leading to the formation of a cyclic chloronium ion intermediate. This process is crucial for understanding how alkenes can undergo transformations to form more complex products.
Recommended video:
Guided course
09:23
1,2 vs 1,4 Addition
Stereochemistry
Stereochemistry refers to the study of the spatial arrangement of atoms in molecules and how this affects their chemical behavior. When alkenes react with Cl₂, the addition can lead to the formation of stereoisomers, such as enantiomers or diastereomers, depending on the configuration of the resulting product. Understanding stereochemistry is essential for predicting the specific products formed during the reaction.
Recommended video:
1:38Polymer Stereochemistry Concept 1
Halogenation of Alkenes
Halogenation of alkenes is a specific type of electrophilic addition reaction where halogens, such as chlorine or bromine, add across the double bond of an alkene. This reaction typically results in the formation of vicinal dihalides, where two halogen atoms are added to adjacent carbon atoms. Recognizing the mechanism and outcome of halogenation is vital for predicting the products of the reaction with Cl₂.
Recommended video:
Guided course
03:45Halogenation Mechanism
2:27mWatch next
Master General properties of halogenation. with a bite sized video explanation from Johnny
Start learningRelated Videos
Related Practice