全合成Azadirachtin的模型研究

一种抑制昆虫食欲的复杂天然产物。

Wedelolactone is a natural product and is one kind of derivatives of Coumestan. Wedelolactone has high bioactivity. Although there are many reports about the synthesis of Coumestan and its derivatives in literature, all these synthesis methods are to specific molecules and there is almost no report about the total synthesis of Wedelolactone. So we designed a more general and efficient synthesis route, which is not only used in the total synthesis of Wedelolactone, but also can be used in the synthesis of other derivatives of Coumestan. We synthesized segment A and B convergently using 3,4-dihydroxybenzyl aldehyde and 2,4,6-trihydroxybenzyl aldehyde as starting materials separately, and then finished the total synthesis of Wedelolactone firstly through two key reactions: Sonogashira coupling and Carbonative Annulation. The total yield is 53% from the longest synthesis route (9 steps).