**NaOH/NaOEt**: pKaH ~16; partial enolate of ketone (~5%); used in aldol and Claisen. - **NaH**: pKaH ~35; complete deprotonation of ketones, esters, β-dicarbonyls. - **LDA (lithium diisopropylamide)**: pKaH ~36; bulky; selective for less-hindered α-H (kinetic enolate). The standard for α-alkylation