Alumina is a heterogeneous catalyst for the regioselective epoxidation of terpenic diolefins that deactivates in presence of water. The reactions can be carried out at high temperature, above the boiling point of the solvent, increasing the pressure to maintain the reaction mixture in the liquid phase, yielding conversions between 41% and 96% and selectivities between 19% and 75% to monoepoxides with a significant decrease of reaction times. Deactivated alumina was analyzed, and an effective regeneration method was proposed. Furthermore, to improve the monoepoxide productivity, the effects of temperature, pressure, stirring rate, water concentration, alumina loading, and reactive concentrations were studied.