摘要
Osthole is a natural coumarin derivative and has a broad scope of biological activities. Two series of novel fused osthole analogues were designed, and synthesized through a highly efficient microwave-promoted synthetic proto- col via the reaction of 4-hydroxycoumarins and fl-ketoesters. The reaction conditions including solvent, catalyst, microwave power and irradiation time were also optimized. The pyrano[3,2-c]chromene-2,5-diones and furo[3,2-c]- coumarins were obtained through two distinct intramolecular cyclization processes, and the proposed mechanism was also discussed.
Osthole is a natural coumarin derivative and has a broad scope of biological activities. Two series of novel fused osthole analogues were designed, and synthesized through a highly efficient microwave-promoted synthetic proto- col via the reaction of 4-hydroxycoumarins and fl-ketoesters. The reaction conditions including solvent, catalyst, microwave power and irradiation time were also optimized. The pyrano[3,2-c]chromene-2,5-diones and furo[3,2-c]- coumarins were obtained through two distinct intramolecular cyclization processes, and the proposed mechanism was also discussed.
