chapter 22. the chemistry of enolate ions, enols, and αβ ... materials... · chapter 22. the...
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Chapter 22. The Chemistry of Enolate Ions, Enols, and α,β-Unsaturated Carbonyl
Compounds
Acidity of carbonyl compounds
An orbital interaction of acetaldehyde
Acid- or base-catalyzed enolization
Base-catalyzed
Acid-catalyzed
Racemization through enolization Acid-catalyzed
Base-catalyzed
For comparison: Br2 addition to alkenes
Haloform Reactions
Prepare α,β-unsaturated carbonyl compounds using aldol condensation
Claisen Condensation
Rainer Ludwig Claisen
Dieckmann condensation: intramolecular Claisen condensation
Walter Dieckmann
University of Munich
Crossed Claisen condensation
Conjugate addition reactions with ester and nitrile
Acid-catalyzed conjugate addition reactions
1,2- vs 1,4-additionWith 1,3-butadiene
With α,β-unsaturated carbonyl compounds
Comparison between conjugate addition and carbonyl addition
Thermodynamic control vs. kinetic control products
Robinson Annulation
Reduction with LAH is kinetically controlled
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