Synthesis of the carbon skeleton of the griseorhodins

A synthetic strategy to access the carbon skeleton of the griseorhodin family of natural products has been developed. The key step involved the acid-mediated spirocyclisation of a highly functionalised dihydroxyketone. The delicate electronic balance between the electron rich naphthalene moiety and the electron-withdrawing isocoumarin ring system were finely tuned to facilitate the acid-mediated spirocyclisation reaction. The development of this synthetic strategy provides a basis for further synthetic investigations towards the more structurally complex griseorhodin natural products.