Diversity in Platinum-Catalyzed Hydrative Cyclization of Trialkyne Substrates To Form Tetracyclic Ketones

We report a one-pot synthesis of tetracyclic ketones via PtI2-catalyzed hydrative cyclization of trialkyne functionalities.
These triyne substrates bear an electron-rich aryl group at
the outer alkyne to direct the initial hydration occurring at
the adjacent alkynyl carbon. This tandem catalysis is proposed to comprise two alkyne hydrations, an alkyne insertion
and an intramolecular aldol condensation.