Reduction of a few substituted cyclohexanones adsorbed on size classified high carbon ash fractions from a stoker fired boiler of a thermal power station using NaBH4 as the reducing agent with ethanol as the medium resulted in the formation of two epimeric alcohols. However; trans-4-t-butyl and trans-4-methylcyclohexanols are exclusively formed when the corresponding ketones adsorbed on one particular size classified ash fraction are reduced with NaBH4. In all other cases, a fairly high degree of stereoselectivity has been obtained. It has been observed that low carbon ash does not activate the ketones towards similar stereoselectivity, clearly establishing that the high carbon ash has a definite role to play. The stereochemical outcome of the reductions has been rationalized on the basis of a probable transition state involving Lewis/Bronsted ousted acid sites present in the ash. Mesopores and macropores present in the ash are most likely to act as pockets for adsorption of ketones. Product analysis has been carried out using (HNMR)-H-1 and (CNMR)-C-13.