Synthetic paths towards scalaranes: Assembling the scalaranic skeleton and further transformations

Abstract

The family of scalaranic sesterterpenoids has been known since the early 70s, but they have attracted the attention of synthetic organic chemists only in the last decade. These marine natural products are considered secondary metabolites of marine organisms and have shown promising biological properties. Synthetic approaches towards scalaranes are discussed in the present review. Scalaranes are quite complex compounds, with many chiral centers and their transformations are strongly directed by steric effects of different functional groups attached to the tetracyclic framework. Therefore, methods of assembling the scalaranic skeleton are examined first, followed by the synthesis of natural products or their analogues on the basis of the available tetracyclic template.