A condensation reaction process and reactor for converting a plurality of reactants to at least one reaction product having a vapor pressure less than the vapor pressure of the reactants. The process includes heating a liquid phase of the reactants to at least partial vaporization thus forming a vapor phase of the reactants. The vapor phase reactants are passed in a vapor and or condensed state through at least one catalyst bed spaced from the liquid state to form reaction product(s). The reaction product(s) is returned to the liquid phase without additional contact with catalyst.