This Small Business Innovation Research (SBIR) Phase I project is in the general area of physical organic chemistry and in the subfield of catalysis. The goal of this research is to ascertain the feasibility of catalyzing a commercially important class of chemical reactions through the application of ultrasound. Diels-Alder reactions represent a class of chemical processes that are synthetically quite useful but which have such inherently slow rates of reaction that they are of limited commercial utility. Energy & Minerals Research Company will investigate whether the application of ultrasonic energy to Diels-Alder reaction mixtures will accelerate their rates of reaction sufficiently to enable their broader use in larger scale commercial synthetic chemistry. Four different Diels-Alder systems, chosen to represent a broad range of reactivities, will be studied under identical conditions as a function of sonic intensity. This Phase I effort should determine whether the rates of a range of Diels-Alder reactions can be promoted sonochemically. Additionally, the electric power requirements to catalyze these reactions will be determined and the economic feasibility of the approach evaluated. The successful and economically feasible catalysis of Diels-Alder reactions by ultrasound would add significantly to the synthetic capability of commercial synthetic chemistry.