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With the use of four- to eight-fold functionalized dodecahedranes (1−3), opportunities to arrive at highly strained dodecahedranes with two to four pairs of vicinal, eclipsed bromine substituents through front-side substitution and addition reactions have been explored. In standard processes, the interception of β-OCH3 radical/cationic intermediates was not problematic (9−12, 37, 50). The interception of β-CO2R radicals was possible for Cl• (18) but not for Br• (17). The interception of β-chloro radicals was possible for Cl• (27) but not for Br• (26), and the interception of β-Br cations (“bromonium ions”) with Br- was modest (45) to highly inefficient (24, 26). Two X-ray structural analyses (dimethoxy dibromide 9 and tetramethoxy tetrabromide 53) indicated the structural consequences of the molecular strain introduced by the two (four) vicinal CH3O/Br pairs. A systematic analysis of the MS spectra confirms that, in virtually all cases studied, the elimination of the substituents occurs without significant carbon-cage disruption, leading ultimately to multiply unsaturated dodecahedral ions for dodecahedrahexa(C20H8)enes, -hepta(C20H6)enes, and -octa(C20H4)enes.

From Pagodanes to Dodecahedranes -Search for a Serviceable Access to the Parent (C20H20) Hydrocarbon. --(BERTAU, M.; WAHL, F.; WEILER, A.; SCHEUMANN, K.; WOERTH, J.; KELLER, M.; PRINZBACH, H.; Tetrahedron

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