 The acidity of the α-hydrogen also allows ketones and other carbonyl compounds to react as nucleophiles at that position, with either stoichiometric and catalytic base.Using very strong bases like lithium diisopropylamide (LDA, p"K"a of conjugate acid ~36) under non-equilibrating conditions (–78 °C, 1.1 equiv LDA in THF, ketone added to base), the less-substituted "kinetic" "enolate" is generated selectively, while conditions that allow for equilibration (higher temperature, base added to ketone, using weak or insoluble bases, e.g., NaOEt in EtOH, or NaH) provides the more-substituted "thermodynamic enolate".Ketones are also weak bases, undergoing protonation on the carbonyl oxygen in the presence of Brønsted acids.