Tribenzo[a,c,e]cyclooctene oligomers, which are potential precursors for synthesis of negatively curved nanographenes and nanobelts, have been designed and synthesized. The key to this synthesis is connecting 1,3‐di(4‐t‐butylphenyl)‐dibenzo[e,i]‐2H‐cyclopentacycloocten‐2‐one, dibenzo[3,4 : 7,8]cycloocta[1,2‐c : 5,6‐c′]difuran and the Sondheimer‐Wong diyne through Diels‐Alder reactions. As revealed by X‐ray crystallography, the trimer with a C8−C6−C8−C6−C8 backbone is shaped like a letter C in the crystalline state.