the common intermediate 1. Central to the synthetic approach is a regioselective gold(I)-catalyzed 6-endo-dig cyclization strategy for the construction of isocoumarin skeleton. The other key steps in this approach included Sonogashira coupling, Tsuji-Wacker oxidation, Evans-Saksena's 1,3-anti-reduction and Narasaka-Prasad's 1,3-syn-reduction. The synthetic results unambiguously confirmed the absolute
(-)-邻甲基异
香豆素(2),(-)-邻甲基异
香豆素(3),12-表-异异
香豆素(4),(-)-异皮质
香豆素A(5)和B(6)的统一简洁的第一不对称全合成。已从通用中间体1完成。合成方法的中心是区域选择性
金(I)催化的6-内切-挖掘环化策略,用于构建异
香豆素骨架。该方法的其他关键步骤包括Sonogashira偶联,Tsuji-Wacker氧化,Evans-Saksena的1,3-抗还原和Narasaka-Prasad的1,3-syn还原。合成结果清楚地证实了
天然产物黏膜异
香豆素A和B在C-10和C-12处的绝对立体
化学分别为(-)-(10R,12S)-5和(+)-(10S,12S)-6 。