Formation of Novel Polycyclic Aromatic Compounds by Scholl Reactions of Di(1-anthryl) Ketones via Cyclization and Rearrangement

The Scholl reactions of di(1-anthryl) ketones were performed with chloranil under an acidic condition. The reaction of the parent ketone gave a cyclized product containing a seven-membered ring, which was enantiomerically separable. In contrast, the reaction of 4-(mesityloxy)-1-anthryl derivative mainly afforded an unexpected polycyclic aromatic ketone consisting of eight six-membered rings via skeletal rearrangement. The structure and properties of these products and the reaction mechanism are reported. Two di(1-anthryl) ketones gave different dehydrocyclization products upon treatment with chloranil. In particular, the (2,4,6-trimethylphenyl)oxy substituted derivative produced a novel aromatic ketone via unexpected skeletal rearrangement. This result is in contrast to that of the substituent free derivative, which formed a simple cyclization product with a helical structure.