Enols and Enolates Substitutions and Condensations of Ketones and Aldehydes
Tautomerization Accelerated in Acid
-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 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 H’s, 2 Alkylations; Determine the Product of the Synthesis
All -keto acids are unstable and Decarboxylate
Enamines can be Alkylated
Alkylation of an Enamine Position is Activated
Complements LDA Reaction
LDA vs. Enamine Reaction
Selenation: Formation of -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 - Unsaturated Ketone
Robinson Annulation: Michael Addition followed by Aldol Consensation