Synthesis
The general procedure for the synthesis of 2H-pyran-2,4,6(3H,5H)-trione from 1,3-acetone dicarboxylic acid was as follows: 40 g (0.27 mol) of 1,3-acetone dicarboxylic acid was slowly added to a mixed solution of 60 mL acetic acid and 43 mL acetic anhydride at 0 °C. Continuous stirring was required during the reaction and the reaction temperature was strictly controlled not to exceed 10 °C. With the slow dissolution of 1,3-acetonedicarboxylic acid, a light yellow precipitate gradually formed in the reaction system. After 3 h of reaction, the product was separated by filtration and washed sequentially with 30 mL of glacial acetic acid and 100 mL of benzene. Finally, the obtained white powder was dried under high vacuum to obtain 30 g of 1,3-acetonedicarboxylic anhydride in 86% yield.
References
[1] Asian Journal of Chemistry, 2014, vol. 26, # 22, p. 7867 - 7868
[2] Tetrahedron Letters, 1982, vol. 23, # 19, p. 1971 - 1974
[3] Journal of Medicinal Chemistry, 2001, vol. 44, # 16, p. 2619 - 2635
[4] Patent: US6353105, 2002, B1. Location in patent: Page column 23
[5] Organic Letters, 2011, vol. 13, # 15, p. 3876 - 3879
