8. ADDITION REACTIONS Reactions of alkenes and alkynes

OBJECTIVES 1. Describe mechanisms for addition reactions of alkenes and alkynes. 2. Predict the structure of the product(s) of addition reactions.

REVIEW S:8.1 Addition Reactions

Alkenes are Basic and Nucleophilic

ADDITION OF HYDROGEN HALIDES TO ALKENES Prob:8.29,33 Reaction

Mechanism

Regiochemistry Markovnikov’s rule

Stability of Carbocations

Anti-Markovnikov Addition

Stereochemistry of H–Hal Addition to Alkenes

HWeb Answer HWeb Answer HWeb27 Question 1. What would be the major organic product from the following reaction? 1. A 2. B 3. C 4. D HWeb Answer

HWeb Answer HWeb Answer HWeb27 Question 2. What would be the major organic product from the following reaction? 1. A 2. B 3. C 4. D HWeb Answer

ACID-CATALYZED HYDRATION OF ALKENES Prob:8.28 Addition of Sulfuric Acid

Addition of Water

ADDITION OF BROMINE AND CHLORINE TO ALKENES Prob:8.41 Overview

Stereochemistry

Mechanism

Formation of Halohydrins

Mechanism

HWeb Answer HWeb Answer HWeb28 Question 1. The anti addition of bromine leads to the formation of trans 1,2- dibromo products from cyclic alkenes. Which statement is true concerning this process? 1. The highly electophilic halogen causes anti addition. 2. The formation of the bromonium ion leads to trans addition. 3. The trans product forms in one step because it is more stable. 4. The bromonium ion intermediate is attacked in a SN2 manner by bromide. HWeb Answer

HWeb Answer HWeb Answer HWeb28 Question 2. What would be the major organic product from the following reaction. 1. A 2. B 3. B and C 4. D HWeb Answer

ADDITION OF CARBENES TO ALKENES I-CH2-I I-CH2-Zn-I

Addition to Alkenes

OXIDATION OF ALKENES syn Hydroxylation S:8.10,11 Prob:8.27,31,32,35,39,40,46,47 syn Hydroxylation

Oxidative Cleavage

ADDITION TO ALKYNES Addition of Br2 and Cl2 Addition of H–Hal

Oxidative Cleavage

HWeb Answer HWeb Answer HWeb29 Question 1. What would be the major organic product from the following reaction? 1. A 2. B 3. C 4. D HWeb Answer

HWeb Answer HWeb Answer HWeb29 Question 2. What would be the major organic product from the following reaction? 1. A 2. B 3. C 4. D HWeb Answer

SYNTHETIC STRATEGIES Add to your chart of organic reactions S:8.15 Prob:8.21-26,37 Add to your chart of organic reactions

HWeb Answer HWeb Answer HWeb30 Question 1. What is the product of the addition of one mole of bromine to one mole of 2-butyne? 1. E-1,2-dibromo-2-butene 2. E -1,2-dibromo-1-butene 3. E-2,3-dibromo-2-butene 4. Z-2,3-dibromo-2-butene HWeb Answer

HWeb Answer HWeb Answer HWeb30 Question 2. What is the product of the addition of two moles of hydrogen bromide to one mole of 2-butyne? 1. 1,2-dibromobutane 2. 1,4-dibromobutane 3. 2,3-dibromobutane 4. 2,2-dibromobutane HWeb Answer

CHAPTER 8 ON EXAM 4 Types of Questions - Describe addition reaction mechanisms - Predict the products of addition reactions The problems in the book are good examples of the types of problems on the exam. Preparing for Exam 4: - Work as many problems as possible. - Work in groups. - Do the “Learning Group Problem” at the end of the chapter. - Work through the practice exam