of polycyclic alkaloids. The first total synthesis now proves that the structure of this compound had originally been misassigned. The route to (−)-1 is based on a double Michael addition for the formation of the bridged diazadecalin core and a palladium-catalyzed decarboxylative allylation to install the quaternary bridgehead center. Ring-closing alkyne metathesis allowed a 13-membered cycloalkyne
Xestocyclamine A ((-)-1) 在导致一大类多环
生物碱的
生物合成途径中占有突出地位。现在第一次全合成证明该化合物的结构最初被错误分配。到 (-)-1 的路线基于双迈克尔加成以形成桥接二氮杂
萘烷核心和
钯催化脱羧烯丙基化以安装四元桥头中心。闭环
炔烃复分解允许锻造 13 元环
炔烃,在用于闭合 11 元环的
硼氢化/选择性原脱
硼酸化/烷基-铃木偶联的相关序列中选择性还原。晶体学数据证明合成 (-)-1 与标称的 xestocyclamine 相同,但光谱与真实
生物碱的光谱不同。为了澄清这一点,