Synthesis of Bis‐spiro Cyclopropanes Based on Meldrum’s Acid by Milling

Abstract

Abstract Reaction of 2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione (Meldrum’s acid) with various solid aldehydes in the presence of cyanogen bromide and solid sodium ethoxide (EtONa) leads to the selective and efficient formation of bis‐spiro cyclopropanes based on Meldrum’s acid at the range of 0 °C to room temperature. The products were obtained in good to excellent yields. Structure elucidation is carried out by 1 H NMR, 13 C NMR, FT‐IR spectroscopy, mass analyses and X‐ray crystallography techniques. A possible mechanism for the formation of products is also discussed under solvent‐free condition.