Lactonization reaction of 2-carboxystilbene mediated by copper(II) chloride proceeded regiospecifically to give the five-membered lactone, while the bromolactonizations using N-bromosuccinimide and anodic oxidation were found to furnish the six-membered lactone. Using these regiospecific lactonization reactions as a key step, antiallergic and antimicrobial isocoumarins and the benzylidenephthalides thunberginols A and F and their 3'-deoxyanalogs were synthesized from phyllodulcin and hydrangenol.Two phthalides called hydramacrophyllols A and B were isolated from Hydrangeae Dulcis Folium and their stereostructures were determined on the basis of physicochemical and chemical evidence, which included the syntheses of hydramacrophyllols A and B from hydrangenol by the application of the lactonization method using copper(II)chloride. In addition, hydramacrophyllols A and B were found to exhibit an inhibitory effect on the histamine release from rat peritoneal exudate cells induced by antigen-antibody reaction.
氯化
铜(II)介导的 2-羧基
二苯乙烯的内酯化反应进行了区域特异性反应,生成了五元内酯,而使用 N-
溴代琥珀
酰亚胺和阳极氧化进行的
溴内酯化反应则生成了六元内酯。利用这些区域特异性内酯化反应作为关键步骤,从phyllodulcin 和 hydrangenol 合成了抗过敏和抗菌的异
香豆素和苯亚甲基
酞thunberginols A 和 F 及其 3'-deoxyanalogs 。根据物理
化学和
化学证据,从绣线菊叶中分离出了两种名为
水飞蓟醇 A 和 B 的
邻苯二甲酸盐,并确定了它们的立体结构,其中包括应用
氯化
铜(II)内酯化法从
水飞蓟醇合成了
水飞蓟醇 A 和 B。此外,还发现
水合麦考
酚 A 和 B 对抗原-
抗体反应诱导的大鼠腹腔渗出细胞释放
组胺具有抑制作用。