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Ch. 12 - Radicals
Bruice - Organic Chemistry 8th Edition
Bruice8th EditionOrganic ChemistryISBN: 9780135213711Not the one you use?Change textbook
All textbooksBruice 8th EditionCh. 12 - RadicalsProblem 31b
Chapter 13, Problem 31b

What is the major product of the following reactions? Disregard stereoisomers:
b.

Verified step by step guidance
1
Step 1: Recognize the reagents and conditions. NBS (N-Bromosuccinimide) is used for allylic or benzylic bromination in the presence of a radical initiator, such as peroxide and heat.
Step 2: Identify the allylic position in the molecule. The allylic position is the carbon atom adjacent to the double bond in the cyclopentene structure.
Step 3: Understand the mechanism. The reaction proceeds via a radical mechanism. Peroxide and heat generate radicals, which abstract a hydrogen atom from the allylic position, forming an allylic radical.
Step 4: Bromine from NBS reacts with the allylic radical to form the major product. The bromine atom attaches to the allylic position, resulting in an allylic bromide.
Step 5: Consider resonance stabilization. The allylic radical is resonance-stabilized, so bromination can occur at either of the two equivalent allylic positions. Disregard stereoisomers as instructed.

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Key Concepts

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

Reaction Mechanisms

Understanding reaction mechanisms is crucial in organic chemistry as they describe the step-by-step process by which reactants transform into products. This includes identifying intermediates, transition states, and the movement of electrons. Familiarity with mechanisms helps predict the major products of reactions based on the stability of intermediates and the energy changes involved.
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Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. Recognizing functional groups allows chemists to predict how a compound will react in a given reaction. Different functional groups can influence the reactivity and the type of products formed during chemical reactions.
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Regioselectivity

Regioselectivity refers to the preference of a chemical reaction to occur at one location over another in a molecule. This concept is essential for predicting the major product of a reaction, as certain pathways may lead to more stable or favorable products. Understanding regioselectivity helps in determining which isomer will be formed when multiple possibilities exist.
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Related Practice
Textbook Question

When 2-methylpropane is monochlorinated in the presence of light at room temperature, 36% of the product is 2-chloro-2-methylpropane and 64% is 1-chloro-2-methylpropane. From these data, calculate how much easier it is to remove a hydrogen atom from a tertiary carbon than from a primary carbon under these conditions.

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Textbook Question

What is the major product of the following reactions? Disregard stereoisomers:

a.

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Textbook Question

What are the answers to Problem 29 when the same compounds are treated with Br2 at 125 °C?

c.

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Textbook Question

What is the major product of the following reactions? Disregard stereoisomers:

d.

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Textbook Question

What is the major product obtained from treating an excess of each of the following compounds with Cl2 in the presence of ultraviolet light at room temperature? Disregard stereoisomers.

c.

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Textbook Question

What is the major product of the following reactions? Disregard stereoisomers:

c.

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