Double-stranded cycles: Toward C₈₄'s belt region

The reactivity of the double-stranded hydrocarbon cycle with two ether bridges (1) toward iodotrimethylsilane (TMSI) was investigated in some detail. The carbon skeleton of cycle 1 resembles the belt region of a C₈₄ fullerene which makes it a potential precursor to the long sought after fully aromatic derivative. Upon exposure to TMSI, cycle 1 undergoes a cascade of reactions which involve different states of iodination/reduction which ultimately lead to the hydrogenated cycle 5a, whose structure was proven by single-crystal X-ray analysis. A deeper insight into mechanistic aspects of this sequence of conversions was gained by performing the reaction under dry and wet conditions, whereby the latter involved both normal and deuterated water. With the help of detailed NMR correlation studies and DFT computations, all important aspects were clarified including an unexpected selective H/D exchange at the naphthalenic moieties.