Abstract:

Pimarane-type diterpenes, such as pimara- 8,15-diene (1) and pimaradienoic acid (5) (figure 1), are mainly isolated from conifer oleoresin. This class of compounds has shown interesting biological activities, e.g. analgesic, anti-tumor, antiinflammatory, vasorelaxant, antimicrobial activities, anti-Alzheimer and antioxidant effects. Due to the importance of this class, several research groups have already proposed total synthesis of those substances. Thus, we decided to study the synthesis of these compounds from two main constituents of Copaiba oil, copalic acid (7) and ent-agathic acid (8) (figure 2).