Four‐Center Two‐Electron Bonding in a Tetrahedral Topology. Experimental Realization of Three‐Dimensional Homoaromaticity in the 1,3‐Dehydro‐5,7‐adamantanediyl Dication
A nonclassical structure for the dication 3 is supported, in particular, by the 13C-NMR data: the signals of the bridgehead C atoms are shifted upfield (δ = 6.6) and not downfie...