作者:Todd S. McDermott、Andrew A. Mortlock、Clayton H. Heathcock
DOI:10.1021/jo951647i
日期:1996.1.1
The pentacyclic marine alkaloids (-)-papuamine (1) and (-)-haliclonadiamine (2) have been prepared by total synthesis. The synthesis began with (-)-8, which was converted into diester 20 by way of bis-mesylate 17, dinitrile 18, and diacid 19. Dieckmann cyclization of 20 provided keto ester 21, which was transformed into acetal 22. After hydrolysis of the acetal, ketone 25 was subjected to reductive
五环海洋生物碱(-)-巴胺(1)和(-)-卤代二胺(2)是通过全合成制备的。合成开始于(-)-8,其通过双甲磺酸酯17,二腈18和二酸19转化为二酯20。狄克曼环化20提供了酮酸酯21,将其转化为缩醛22。缩醛酮25用1,3-丙二胺和三乙酰氧基硼氢化钠进行还原胺化,得到二胺26和27,为非对映异构体的71∶29混合物,有利于具有木瓜胺相对构型的对称异构体。将二胺转化为它们的t-Boc衍生物后,将苄基醚裂解,并将生成的二醇氧化为二醛30。应用Seyferth方法将醛转化为炔烃,得到二炔31和32的混合物。从31除去t-Boc保护基后,将二氨基二炔15用三丁基锡烷和偶氮异丁腈处理,得到双乙烯基锡烷34。在空气存在下,将这种化合物与Pd(II)和Cu(I)合成,生成(-)-巴布胺(1)。从不对称异构体32获得(-)-卤代二胺(2)。合成生物碱的NMR谱图与天然生物碱的真实样品的NMR谱图相同。