Helical fused anthracenes were elongated by fusing additional aromatic units at both ends to yield novel expanded helicenes. Compounds [5]HA2N and [7]HA consisting of 19 and 21 benzene rings, respectively, were synthesized by fourfold cycloisomerization of the corresponding terminal alkyne precursors. The helical structures were confirmed by X-ray crystallographic analysis, where the aromatic frameworks stacked effectively with the helical turn numbers exceeding two. The enantiomers of the two compounds were resolved by chiral HPLC. Whereas [5]HA2N readily underwent enantiomerization at room temperature at the barrier to enantiomerization of 91 kJ mol