Investigation on Heterogeneous Catalytic Elimination of Lactones over Supported Magnesium Iodide.

The elimination of lactones is a crucial method for preparing corresponding cycloalkane derivatives, but the commonly used catalyst NaI is unstable and non-recyclable. In this work, reusable MgI2@SiO2 was prepared for heterogeneous catalytic lactone elimination. Cyclopropyl methyl ketone was synthesized from 2-acetyl-γ-butyrolactone using MgI2@SiO2 as a catalyst at 180 °C and 1 atm. The yield and selectivity were both over 99%. The activity of MgI2@SiO2 was estimated to be 11 times that of NaI. The high activity of MgI2@SiO2 is attributed to the Lewis hard acidity of Mg2+ and the soft basicity of I−. The high selectivity of Cyclopropyl methyl ketone comes from the faster reaction rate, and its good stability is due to the strong interactions between Mg2+ and I− with the carrier. This work provides a feasible scheme for the efficient and low-cost elimination synthesis of corresponding cycloalkanes from lactones. [ABSTRACT FROM AUTHOR]