| abstract |
Mixtures of the E and Z isomers of aryl alkyl oximes are converted to 98% or greater E isomer by a process comprising treating a solution of a mixture of E and Z isomers in an organic solvent with a protic or Lewis acid, under anhydrous conditions, to precipitate >98% pure E isomer of an immonium complex and treating (neutralizing) the precipitate with an excess of dilute organic/inorganic base, such as Na 2 CO 3 or NaHCO 3 . The E isomer of the ketoxime is a precursor for highly insecticidal ketoximinoethers. |