Unusual cyclic terpenoids with terminal pendant prenyl moieties: from occurrence to synthesis

Covering: 1966 up to the end of 2013 The paper reviews the known examples of cyclic terpenoids produced from open chain polyenic precursors by an "unusual" biosynthetic pathway, involving selective electrophilic attack on an internal double bond followed by cyclization. The resulting compounds possess cyclic backbones with pendant terminal prenyl groups. Synthetic approaches applied for the synthesis of such specifically functionalized compounds are also discussed, as well as biological activity of reported representatives. A group of terpenes are produced biosynthetically from linear precursors via an electrophilic cyclization initiated on internal double bonds, resulting to cyclic structures with terminal pendant prenylation. They originate exclusively from lower plants and marine organisms.