ABSTRACT. Various diverse heterocyclic oximes of 3-alkyl-2,6-diarylpiperidins, tetrahydrothiopyrans, and tetrahydropyran-4-ones are synthesized using a mortar and pestle in dry media catalyzed by activated fly ash in excellent yields and are characterized by melting point, elemental analysis, MS, FT-IR, and 1 H NMR spectroscopic data.