作者:Martina Würdemann、Jens Christoffers
DOI:10.1039/b922827f
日期:——
Spirocyclic carbazole- and acridine-lactams were prepared by Fischer-indole or Friedländer-quinoline synthesis starting from spirocyclic ketones with a lactam ring. All annulation products were obtained as mixtures of separable regioisomers, which differ only in the position of one methyl group. The starting materials were prepared from 2-pyrrolidone and 2-piperidone by a sequence of protection (by N-allylation), α-acylation, iron-catalyzed Michael reaction followed by Robinson-annulation, palladium-catalyzed N-deprotection and catalytic hydrogenation. The overall yields of this six-step sequence are 13 and 17%, respectively, and the racemic ketones are obtained as single diastereoisomers.
以带有内酰胺环的螺环酮为起点,通过费舍尔-吲哚或弗里德拉德-喹啉合成法制备了螺环咔唑内酰胺和吖啶内酰胺。所有环化产物都是可分离的区域异构体的混合物,它们仅在一个甲基的位置上有所不同。起始材料是由 2-吡咯烷酮和 2-哌啶酮通过一系列保护(N-烯丙基化)、α-酰化、铁催化迈克尔反应后的罗宾逊环化、钯催化 N-脱保护和催化加氢反应制备而成的。这六个步骤的总产率分别为 13% 和 17%,并以非对映异构体的形式得到外消旋酮。