Preparation and First X-ray Structure of a Zirconocene β-Keto Ester Enolate

The reaction of methyl 2-ethylbutyrate with an equimolar amount of lithium diisopropylamide (LDA) leads to the formation of the lithium enolate of methyl 2,2,4-triethyl-3-oxohexanoate. Further reaction with bis(cyclopentadienyl)zirconium(methyl)chloride yields a crystalline zirconocene enolate complex, the structure of which was determined by X-ray diffraction.