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p. 251. Alkenes & Alkynes. Prepapration of alkenes 1. Dehydrohalogenation 2. Dehydration. Alkenes & Alkynes. Reactions of alkenes & alkynes A. Electrophilic Additions Hydrohalogenation i. alkenes ii. alkynes 2. Halogenation i. alkenes ii. alkynes Halohydrins i. alkenes

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p. 251


Alkenes & Alkynes

  • Prepapration of alkenes

    • 1. Dehydrohalogenation

    • 2. Dehydration


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • Hydrohalogenation

  • i. alkenes

  • ii. alkynes

    • 2. Halogenation

  • i. alkenes

  • ii. alkynes

    • Halohydrins

  • i. alkenes

  • ii. alkynes

    • 4. Hydration

  • i. alkenes

  • ii. alkynes


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • Hydrohalogenation

  • i. alkenes

  • ii. alkynes


Electrophilic addition of Br2 to an alkene


p. 217


p. 218


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • 2. Halogenation

  • i. alkenes (working backwards)


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • Halohydrins

  • i. alkenes


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • Halohydrins

  • ii. alkynes


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • 4. Hydration

  • i. alkenes

  • a. acid catalyzed


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • 4. Hydration

  • i. alkenes

  • a. hydroboration & oxidation


p. 223


+

+

-

-

d

d

d

d

Fig. 7-4, p. 225


Jmol


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • 4. Hydration

  • i. alkynes

  • a. acid catalyzed


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • 4. Hydration

  • i. alkynes

  • b. oxymercuration


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • A. Electrophilic Additions

    • 4. Hydration

  • i. alkynes

  • a. hydroboration & oxidation


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • B. Reductions

    • 1. Alkenes

  • i. Catalytic hydrogenation


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • B. Reductions

    • 1. Alkynes

  • i. Catalytic hydrogenation

  • a. Complete reduction


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • B. Reductions

    • 1. Alkynes

  • i. Catalytic hydrogenation

  • b. Lindlar’s catalyst (partial reduction)


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • C. Reductions

    • 1. Alkynes

  • ii. Dissolving metal reduction (partial reduction)


epep !


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • C. Alkyne alkylation


Fig. 8-19, p. 292


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • D. Carbene addition


Fig. 7-6, p. 228


Carbenes


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • Introduction


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • 1. epoxidation

  • Peracids (RCO3H)


Epoxide formation through reaction of peracids


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • 1. epoxidation

  • ii. via halohydrins


The Nobel Prize in Chemistry 2001

"for their work on chirally catalysed hydrogenation reactions"

"for his work on chirally catalysed oxidation reactions"

William S. Knowles

Ryoji Noyori

K. Barry Sharpless


Thalidomide

  • Racemic thalidomide prescribed for morning sickness (1956 – 1961)

  • (R)-enantiomer is an antiemetic

  • (S)-enantiomer is a teratogen


Sharpless epoxidation

(CH3)3COOH


Knowles Asymmetric Reduction


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • 2. dihydroxylation

  • i. osmium tetraoxide


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • 2. dihydroxylation

  • ii. from epoxides


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • 2. Dihydroxylation

    • Application : Synthesis


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • 3. oxidative cleavage

  • i. ozonolysis


p. 237


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • 3. oxidative cleavage

  • i. ozonolysis


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • 3. oxidative cleavage

  • ii. permanganate


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • E. Oxidations

    • 3. oxidative cleavage

  • iii. from diols


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • Introduction


Fig. 8-12, p. 281


Fig. 8-13, p. 282


Fig. 8-14, p. 282


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 1. Addition of HX


Reaction energy diagram for addition of HBr to butadiene


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 2. The Diels-Alder reaction

    • Introduction

    • a. the overall reaction

    • b. history

    • c. nature of the diene and dienophile

    • d. the molecular orbital picture

    • e. conformation of the diene


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 2. The Diels-Alder reaction

    • Introduction

    • a. the overall reaction


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 2. The Diels-Alder reaction

    • Introduction

    • b. history

Albrecht reaction

Liebigs1906, 348, 31.

Staudinger, H.; Bruson, H. A.

Liebigs1926 , 446 , 97.

Diels, O.; Alder, K.

Liebigs. 1928, 460, 98.

Nobel Prize 1950


Otto Paul Hermann Diels

Kurt Alder

The Nobel Prize in Chemistry 1950

"for their discovery and development of the diene synthesis "


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 2. The Diels-Alder reaction

    • Introduction

    • c. nature of the diene and dienophile


p. 286


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 2. The Diels-Alder reaction

    • Introduction

    • d. the molecular orbital picture


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 2. The Diels-Alder reaction

    • Introduction

    • e. the diene conformation


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 2. The Diels-Alder reaction

    • Stereochemistry (Alder’sEndo Rule)


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 2. The Diels-Alder reaction

    • Regiochemistry (The Ortho Rule)


Alkenes & Alkynes

  • Reactions of alkenes & alkynes

  • F. Conjugated Dienes

    • 2. The Diels-Alder reaction

    • Regiochemistry (The Para Rule)


Fig. 8-17, p. 287


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