/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 30 What product would you expect fr... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 10: Problem 30

What product would you expect from the reaction of 1 -phenyl-2-butene with NBS? Explain.

Short Answer

Expert verified
The expected product is 1-phenyl-2-bromo-2-butene, formed by allylic bromination.

Step by step solution

01

Understanding NBS

NBS, or N-bromosuccinimide, is commonly used to brominate allylic and benzylic positions in organic molecules. In this context, we focus on its ability to react with the allylic positions adjacent to double bonds.
02

Analyzing the Structure of 1-Phenyl-2-butene

1-Phenyl-2-butene is an alkene with a phenyl group attached to one side of the double bond. On analyzing the structure, the allylic position (carbon next to the double bond) provides potential sites for bromination.
03

Identifying the Allylic Position

Identify the carbon next to the double bond, which is the allylic position. In 1-phenyl-2-butene, the hydrogen present on the carbon adjacent to the double bond and next to the phenyl group is the site that can be replaced by bromine.
04

Performing the Bromination Reaction

NBS, in the presence of light or heat, abstracts an allylic hydrogen and forms a bromine radical, which adds to the allylic position. The reaction with 1-phenyl-2-butene occurs such that the bromine adds to the allylic position next to the double bond, resulting in 1-phenyl-2-bromo-2-butene.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

N-bromosuccinimide (NBS)
N-bromosuccinimide (NBS) is an important reagent in organic chemistry, particularly known for its role in selective bromination reactions. It has unique properties that make it suitable for reactions at allylic or benzylic sites without affecting other parts of a molecule.
  • NBS decomposes to release a low concentration of bromine radicals under reaction conditions.
  • It is often used in reactions with light or often a radical initiator to facilitate the process.
  • Its selectivity makes it highly useful for targeting specific sites near double bonds.
NBS is particularly valuable for its ease of use and its ability to control the reaction conditions, thus limiting unwanted side reactions.
Organic reaction mechanisms
Understanding organic reaction mechanisms is crucial in predicting how reactants transform into products. In the context of NBS, these mechanisms typically involve radical formations.
When using NBS for bromination, the reaction begins with the generation of a bromine radical. This is triggered by NBS under photolytic or thermal conditions.
  • The bromine radical abstracts a hydrogen atom from an allylic position, forming an allylic radical.
  • The formed allylic radical rapidly combines with another bromine molecule to stabilize, forming the brominated product.
This sequence of radical initiation, propagation, and termination is what allows the selective targeting of electrons and hydrogen atoms adjacent to double bonds.
Allylic position
The allylic position is a key feature in understanding where certain reactions can occur, especially in allylic bromination using NBS. The allylic position refers to the position adjacent to a carbon-carbon double bond.
In molecules like alkenes, carbon atoms attached to the double-bonded carbons are termed allylic carbons. This proximity to the double bond allows stabilization of charge through resonance.
  • The allylic position is often more reactive than non-allylic positions because of this stabilization.
  • In allylic bromination, identifying these sites is crucial as bromine specifically replaces allylic hydrogens.
Recognition of the allylic position allows chemists to predict and control the outcomes of bromination reactions accurately.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Draw structures corresponding to the following IUPAC names: (a) 2 -Chloro-3,3-dimethylhexane (b) 3,3 -Dichloro-2-methylhexane (c) 3 -Bromo-3-ethylpentane (d) 1,1 -Dibromo-4-isopropylcyclohexane (e) \(4-\mathrm{sec}\) -Butyl-2-chlorononane (f) 1,1 -Dibromo- 4 -tert-butylcyclohexane

Addition of HBr to a double bond with an ether (-OR) substituent occurs regiospecifically to give a product in which the \(-\mathrm{Br}\) and \(-\mathrm{OR}\) are bonded to the same carbon. Draw the two possible carbocation intermediates in this electrophilic addition reaction, and explain using resonance why the observed product is formed.

The relative rate of radical bromination is 1: 82: 1640 for \(1^{\circ}: 2^{\circ}: 3^{\circ}\) hydrogens, respectively. Draw all of the monobrominated products that you might obtain from the radical bromination of the compounds below. Calculate the relative percentage of each. (a) methylcyclobutane (b) 3 , 3 -dimethylpentane (c) 3 -methylpentane

How would you prepare the following compounds, starting with cyclopentene and any other reagents needed? (a) Chlorocyclopentane (b) Methylcyclopentane (c) 3 -Bromocyclopentene (d) Cyclopentanol (e) Cyclopentylcyclopentane (f) 1,3 -Cyclopentadiene

How might you replace a halogen substituent by a deuterium atom if you wanted to prepare a deuterated compound?
See all solutions

Recommended explanations on Chemistry Textbooks

Chemical Reactions

Read Explanation

Chemical Analysis

Read Explanation

Physical Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Chemistry Branches

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.