Highly efficient and clean procedure is described for the synthesis of α,α| -bis-(substitutedbenzylidene) cycloalkanones with excellent yields by the reaction of cycloalkanones with aromatic aldehydes using catalytic amount of HBF4-SiO2 as catalyst. The catalyst was easily recovered and reused without loss of activity.

Keywords : α,α| -bis-(substituted-benzylidene) cycloalkanones, HBF4-SiO2, solvent-free conditions.