Solvent‐free Darzens condensation of 3‐chlorooxindoles with aryl aldehydes for diastereoselective construction of spiro‐epoxyoxindoles by grinding

Abstract A highly efficient, diastereoselective strategy for the synthesis of aryl‐substituted spiro‐epoxyoxindole derivatives by a Darzens‐type reaction of α‐chlorooxindoles with aryl aldehydes in the presence of bases under solvent‐free grinding conditions has been developed. The process features with easy work‐up, mild reaction condition, high to excellent diastereoselectivitie and yields as well as environmental compatibility.