Enols and Enolates a Substitutions and Condensations of
Enols and Enolates a Substitutions and Condensations of Ketones and Aldehydes
Tautomerization Accelerated in Acid
a-Halogenation
Reaction Occurs via Enol
Tautomerization Acceleration in Base
Alkylation in Base Reaction with 1 o RX
Using LDA as Base to form Enolate
Alkylation a to C=O C-alkylation preferred
Alkylation Occurs on Less Hindered Side of C=O
Malonic Ester Synthesis of Carboxylic Acids
H’s are unusually acidic
Decarboxylation (loss of CO 2)
2 Acidic a H’s, 2 Alkylations; Determine the Product of the Synthesis
All b-keto acids are unstable and Decarboxylate
Enamines can be Alkylated
Alkylation of an Enamine a Position is Activated
Complements LDA Reaction
LDA vs. Enamine Reaction
a-Selenation: Formation of a, b-Unsaturated Ketones
Mechanism
Synthesis
Aldol Condensation
Enolate Undergoes Nucleophilic Addition
Aldol Condensation Dimerization of 3 -Pentanone
Crossed Aldol Between 2 Different C=O Compounds
Four Possible Condensation Products
Crossed Aldol Condensation
Dehydration of Aldol Products
Predicting Aldol Dehydration Products
Intramolecular Aldol
Predict the Product
Conjugate Addition
1, 2 - vs. 1, 4 - Addition
Michael Addition Conjugate Addition of Enolate to a, b. Unsaturated Ketone
Robinson Annulation: Michael Addition followed by Aldol Consensation
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