Reactivity and Alkylation of Enolate ions
Start with the big picture
Enolate formation depends on the acidity of α-hydrogens and on the base and conditions used. Kinetic and thermodynamic conditions can favor different enolates in unsymmetrical ketones, while solvent and counter-ion also influence reactivity. Resonance explains why the α-carbon can attack electrophiles; alkylation is most suitable with unhindered primary alkyl halides, whereas competing elimination or O-alkylation can affect outcomes. The broader reaction set includes α-halogenation, aldol and Claisen condensations, Michael addition, and enamine-based α-functionalization. Cyclic systems introduce stereochemical considerations, and controlling polyalkylation or avoiding mixtures is important when planning a synthesis. Together, these principles connect enolate structure and preparation with product selectivity.
What you'll learn
- Describe how bases form enolate ions from carbonyl compounds.
- Compare kinetic and thermodynamic enolate formation and their regioselectivity.
- Explain how resonance gives enolates nucleophilic character at the α-carbon.
- Identify factors that influence C- versus O-alkylation.
- Distinguish major reaction patterns involving enolates and related enamines.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
