The preparation of tricyclobutabenzene and its next two higher homologues is described. The synthetic approach involves the [4+ 21 cycloaddition of dimethyl 1, 2- cyclobutenedicarboxylate to an appropriate diene followed by hydrolysis of the ester functions, bisdecarboxylation, and aromatization. The NMR, ultraviolet, and photoelectron spectra of these small-ring trisannelated benzenes are presented. The properties of all ...
[Doecke, Christopher W.; Garratt, Peter J.; Shahriari-Zavareh, Hooshang; Zahler, Robert Journal of Organic Chemistry, 1984 , vol. 49, # 8 p. 1412 - 1417]