Linearly Fused Dicyclobutabenzenes via Dual, Regioselective Cycloadditions of 1,4-Benzdiyne Equivalent and Ketene Silyl Acetals - Arisawa, Tetsu; Hamura, Toshiyuki; Uekusa, Hidehiro; Matsumoto, Takashi; Suzuki, Keisuke (Synlett, 2008)