sixfold intramolecular Eglinton coupling in the hexabutadiyne precursors obtained by the sixfold Cadiot–Chodkiewicz cross-coupling of hexaethynylbenzene. Its planar structure was revealed by X-ray crystallographic analysis. The full cross-conjugation of the six 18π electron circuits yields the π-electron conjugation along the giant π core. This work provides a realizable method for the synthesis of future