In this thesis have developed a synthetic sequence that led to the confirmation of the structures of metabolites previously isolated from Penicillium brevicompactum, either by total synthesis of the same or similar preparation of substances that make unambiguous assignment of a principle . On the other hand, have used the synthetic routes open for the attainment of different analogues in order to establish structure-activity relationships that allow the optimization of the activities observed for the natural products isolated. This has resulted in confirmation of the important activities by natural products isolation and optimization of the fungicides and insecticides for obtaining synthetic analogues.