Institut für Reine und Angewandte Chemie, Carl von Ossietzky-Universität Oldenburg, D-26111, Oldenburg, Germany.
Org Biomol Chem. 2010 Apr 21;8(8):1894-8. doi: 10.1039/b922827f.
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), alpha-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.
螺环咔唑和吖啶内酰胺通过 Fischer 吲哚或 Friedländer 喹啉合成法，从带有内酰胺环的螺环酮开始制备。所有稠环产物均为可分离的区域异构体的混合物获得，它们仅在一个甲基的位置上有所不同。起始材料通过一系列保护（通过 N-烯丙基化）、α-酰化、铁催化的迈克尔反应，然后进行 Robinson 稠合、钯催化的 N-脱保护和催化氢化，由 2-吡咯烷酮和 2-哌啶酮制备得到。这六步反应的总收率分别为 13%和 17%，并且得到的外消旋酮为单一非对映异构体。
