Circumtrindene:  A Geodesic Dome of Molecular Dimensions. Rational Synthesis of 60 of C₆₀¹

The title compound (1), which had previously been available in only 0.2% yield by flash vacuum pyrolysis (FVP) of decacyclene (2) at 1200−1300 °C, has now been prepared in 25−27% yield by FVP of 3,9,15-trichlorodecacyclene (5b) at 1100 °C. The propeller-shape 5b was synthesized by aldol cyclotrimerization of 8-chloro-1(2H)-acenaphthylenone (8b), which, in turn, was prepared by a simple four-step synthesis from 2-chloronaphthalene. The synthetic strategy demonstrated here, which has improved the yield of circumtrindene (1) by more than 2 orders of magnitude, should be applicable to the rational synthesis of larger geodesic polyarenes, both open (bowls, baskets, tubes, etc.) and closed (fullerenes).