The title compound (15) which has two cyclobutadienes fused to a benzene ring, was synthesized by heating dl-(7), meso-3, 8-di-t-butyl-1, 5, 6, 10-tetraphenyldeca-3, 4, 6, 7- tetraene-1, 9-diyne (8), or E, Z,-3, 4-bis (1-t-butyl-3-phenyl-2-propynylidene)-1, 2-diphenyl-1- cyclobutene (12).