Regioselective functionalization of sumanene

Doubly functionalized dioxosumanene was designed and synthesized to extend π conjugation bi-directionally. Friedel-Crafts double cycloalkylation to sumanene proceeded selectively to give the cycloalkylated compound. This compound was suggested to be the flattened structure as compared to sumanene, which induced the facile bowl-to-bowl inversion. Oxidation of the benzylic position was performed, and then a carbonyl group at the reverse side of the cycloalkylated arene was selectively protected with acetal to afford the doubly functionalized dioxosumanene.

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