A benzannulation reaction of β-diketones with dimethylacetylenedicarboxylate catalyzed by pyridine and potassium tert-butoxide is described. Fully substituted benzenes are synthesized from simple and commercially available starting materials under mild conditions in high yields. benzannulation - dimethylacetylenedicarboxylate - pyridine - β-diketones - potassium tert-butoxide