Cycloaddition of nitrile oxides generated in situ from aldoximes to 2,3-dichloroprop-1-ene in the oxidizing system Oxone®–NaCl–Na2CO3 in aqueous medium afforded 3-organyl-5-(chloromethyl)isoxazoles. The procedure provides high yields of the target products and avoids the use of organic oxidants, bases, and solvents.