Abstract: A combination of an etherification process and a process for the isomerization of linear alkenes to isoalkenes uses a separation zone that receives an effluent stream from the etherification reaction zone and separates it into a high boiling stream, a low boiling stream and an intermediate boiling stream in order to reduce the mass flow of reactants through the isomerization and etherification reaction zones. The separation zone normally has an arrangement of a distillation column. The distillation column can provide a distillation function only, or can also provide a reactive distillation zone. The intermediate boiling stream typically leaves the column as a sidecut which in the case of reactive distillation is taken from the point above a bed of catalyst within the column. Taking the sidecut stream substantially eliminates the circulation of isoalkane hydrocarbons through the etherification and isomerization zone and maintains normal alkanes at an acceptable equilibrium level.