Thermolysis of 6, 6′-(2-oxopropane-1, 3-diyl) bis (2, 2-dimethyl-4H-1, 3-dioxin-4-one) in the presence of methanol gave a triketo-ester which subsequently aromatized to provide a synthetically useful homophthalate ester. Enolate C-acylation in the presence of diethylzinc was used to synthesize other double diketo-dioxinones, which on cyclization, aromatization and dioxinone ring opening gave novel double resorcylate derivatives.