Bicyclo[3.2.1]octa‐2,6‐dienyllithium

The first isolable, crystalline compound containing the bishomoaromatic anion bicyclo[3.2.1]octa-2,6-dienide, the tetramethyl-ethylenediamine adduct of the title compound 1, has Cs symmetry in solution. In crystalline 1, however, the lithium is bonded unsymmetrically to all five sp2 C-atoms. The C2- and C3-bridges are surprisingly close to each other, as is required for bishomoaromaticity; lithium has the unusual coordiation number 7.