Cyclic and acyclic 1, 3, 3′-triketones were prepared by the reactions adopting β-diketones and anhydrides in the presence of barium or strontium hydrides in high yields. Crystal structure of 4-acetyl-2, 2, 6, 6-tetramethyl-3, 5-heptanedione (3a) represented the dorminant keto form and provided evidence for intermolecular C H⋯ O hydrogen bonds (average C⋯ O distance; 3.437 Å, average C H⋯ O angle; 169.25°).