Reactivity of Diterpenoid Quinones: Royleanones.

Naturally occurring abietane diterpenoids have been studied over the years and have shown to display a wide range of biological activities. This review covers three main aspects of the abietane-type diterpenoids with hydroxy-p-quinone C ring, designated as royleanones. An overview of 1) the naturally occurrence, 2) chemical features and 3) the biological activities of this abietane group of compounds, including rearranged derivatives, is here explained. Likewise, hemisynthetic and total synthetic procedures to obtain royleanones will be reviewed. Thus, the chemistry of these bioactive compounds will be emphasized as well as their potential impact in the discovery of new macromolecular targets and novel therapeutic drugs. This review contains about 190 references covering the years from 1962 to 2014 on royleanone studies.