Star-Shaped Polycyclic Aromatic Ketones via 3-Fold Cycloadditions of Isobenzofuran Trimer Equivalent

Three-directional annulations of isobenzofuran trimer equivalent are developed. Importantly, the successive cydoadditions could be controlled under suitable conditions, selectively, affording the dual or triple cycloadduct, which leads to the alternative preparation of the symmetrical and unsymmetrical star-shaped polycyclic aromatic ketones. H-1 NMR analysis of the star-shaped aromatic ketone indicated the pi-pi interactions through the aggregation in solution.