K-L K β-Ketoacid β-Ketoester Ketal Ketal Carbon Ketal Group Keto Form Keto Group Keto-Enol Tautomerism Ketone Ketose Kiliani-Fischer Synthesis Kinetic Conditions Kinetic Control Kinetic Enolate Kinetic Product Kolbe Carboxylation L 1-1 Link 1-4 Link 4-4 Link Lactam Lactol Lactone Lateral Overlap LDA Leaving Group Levorotatory Lewis Acid Lewis Base Lewis Theory Ligand Lindlar Catalyst Linear Overlap Lipid Lithium Aluminumhydride Lithium Diisopropylamide Long-Range Coupling Low-Resolution Mass Spectrum