Selective ionic hydrogenation of alpha,beta-unsaturated carbonyl compounds with alkanes (cyclohexane and others) was previously known to proceed only in superacidic conditions due to the necessity of dicationic, superelectrophilic activation of the enones. In present paper we disclose that H-form zeolites with acidity well below superacidity, are able however to induce the reduction of a,p-unsaturated carbonyl compounds with cyclohexane in strong analogy to the "parent", superacid mediated reactions. The probable interpretation of these results in terms of highly electrophilic (superelectrophilic) intermediates on the solid is discussed. (c) 2005 Elsevier B.V. All rights reserved.