Organic Chemistry

John McMurry

ISBN #9781305080485

9th Edition

1,986 Questions

21,829 Students Helped

Homework Questions

Summary

Learning Objectives

Key Concepts

Example Problems

Explanations

Common Mistakes

Summary

This section covers the preparation and reactions of alkenes. It begins with how alkenes can be formed from alcohols or alkyl halides via elimination reactions such as dehydration and dehydrohalogenation. The text then explores various addition reactions to alkenes, including oxymercuration–demercuration and hydroboration–oxidation – reactions that follow Markovnikov and non-Markovnikov rules respectively. Mechanistic details such as carbocation formation, halonium ion intermediates, and carbene addition provide insights into reaction stereochemistry (syn vs. anti addition). Additionally, applications in polymerization and biological transformations illustrate the importance and versatility of these reactions in both laboratory and industrial settings.

Learning Objectives

Key Concepts

CONCEPT

DEFINITION

Acid–Base Chemistry

The study of acids and bases using both the Brønsted–Lowry (proton-donating/accepting) and Lewis (electron pair accepting/donating) frameworks, including quantification via pKa values, which together explain chemical reactivity in organic molecules. •

Example Problems

Example 1

One problem with elimination reactions is that mixtures of products are often formed. For example, treatment of 2 -bromo-2-methylbutane with $\mathrm{KOH}$ in ethanol yields a mixture of two alkene products. What are their likely structures?

Example 2

How many alkene products, including $E, Z$ isomers, might be obtained by dehydration of 3 -methyl-3-hexanol with aqueous sulfuric acid?

Example 3

What product would you expect to obtain from addition of $\mathrm{Cl}_{2}$ to 1,2 -dimethylcyclohexene? Show the stereochemistry of the product.

Example 4

Addition of $\mathrm{HCl}$ to 1,2 -dimethylcyclohexene yields a mixture of two products. Show the stereochemistry of each, and explain why a mixture is formed.

Example 5

What product would you expect from the reaction of cyclopentene with NBS and water? Show the stereochemistry.