Ethyl 2-oxo-1-cyclooctanecarboxylate (2-carbethoxycyclooctanone) is a β-keto ester. It undergoes Michael addition with 3-buten-2-one (methyl vinyl ketone, MVK) in the presence of potassium bis(1,2-benzenediolato)phenylsilicate to afford the corresponding 1,4-adduct. It can be synthesized from cycloheptanone. Its boiling point, density and refractive index have been determined.