diethyl 2-(4-pentylpiperidin-1-yl)propanedioate

ethyl 4-(3-oxopentan-2-yl)-4H-pyridine-1-carboxylate

ethyl 4-(2-oxocyclohexyl)-4H-pyridine-1-carboxylate

ethyl 4-(2-oxopropyl)-4H-pyridine-1-carboxylate

ethyl 2-(2-oxopropyl)-2H-pyridine-1-carboxylate