- α-Hydrogens in carbonyl compounds are acidic and can be deprotonated to form enolates using bases like KH or LDA. - Enolates are nucleophilic and can undergo reactions like alkylation, halogenation, and aldol condensation. They tautomerize between keto and enol forms. - α,β-Unsaturated carbonyls undergo conjugate additions and other reactions characteristic of alkenes and carbonyl groups. They can rearrange between β,γ and α,β isomers with acid or base catalysis.