Disclosed are processes and systems for oxidizing cycloalkylbenzene such as cyclohexylbenzene to make an oxygenate such as a hydroperoxide thereof. A liquid distributor having multiple liquid ingress ports is used for supplying a cycloalkylbenzene-containing liquid into an oxidation reactor in the form of liquid streams forming part of the reaction medium. A gas distributor distributing an O2-containing gas into the reaction medium in the form of gas streams is preferably located below the liquid distributor. Preferably the gas bubbles upwards in the reaction medium. The agitation and mixing provided by the liquid streams, gas streams/bubbles result in sufficient homogeneity of cycloalkylbenzene concentration, cycloalkylbenzene hydroperoxide concentration, dissolved oxygen concentration, and temperature in the liquid phase.