Synthesis of the Pentacylic Core of (+)-Salvileucalin B

A concise
preparation of the prochiral pentacyclic core of (+)-salvi­leucalin
B is presented. The key feature in the synthesis is the Cu-catalyzed
intramolecular cyclopropanation of a symmetrical indane-derived α-diazo
β-keto ester. This symmetry is carried through the remainder
of the synthesis. This practical approach could allow the ready preparation
of derivatives for further chemical and biological studies of this
class of natural products.