Process for preparing 2-(1-cyclohexenyl)-cyclohexanone

In a process for preparing 2-(1-cyclohexenyl)-cyclohexanone including condensing cyclohexanone in the presence of a strong acid ion exchange catalyst and removing the water formed by distillation of the resulting reaction mixture, the improvement comprising conducting the condensation with a macro-porous ion exchange resin at atmospheric pressure and a temperature of about 50.degree. to 125.degree. C., the macro-porous ion exchange resin comprising a sulfonated copolymer of styrene having 15 to 20% by weight of divinyl benzene therein, and pores having an average pore size in excess of 100A in diameter, or an internal surface area greater than 30 square meters per gram, or both, contacting the cycohexanone with the macro-porous ion exchange resin at a space velocity from 660 to 1320 grams of cyclohexanone per gram of resin per hour, continuing the condensation such that the conversion of the cyclohexanone is maintained at 50% or less, separating the ion exchange resin from the reaction mixture and distilling the reaction mixture to remove the water formed in the absence of the ion exchange resin and recovering the 2-(1-cyclohexenyl)-cyclohexanone product.