STUDIES ON THE SYNTHESIS OF THE INDOLO[2,3-A]QUINOLIZIDINE SYSTEM
STUDIES ON THE SYNTHESIS OF THE INDOLO[2,3-A]QUINOLIZIDINE SYSTEM
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DOI：
10.1021/jo00284a037
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发表时间：
1989-11-10
影响因子：
3.6
通讯作者：
SOLANS, X
中科院分区：
文献类型：
--
作者：
RUBIRALTA, M;DIEZ, A;SOLANS, X
报道了一条合成吲哚并[2，3-o]喹嗪-2-酮环系的新路线。其基于在关键步骤中通过在N-取代的2-（2-吲哚基）-4-哌啶酮衍生物的吲哚3-位上的环化来制备C环。吲哚并[2，3-o]喹嗪环体系由于存在于大量的吲哚生物碱中，因此从合成的角度来看，它受到了极大的关注。[2]吲哚并[2，3-a]喹嗪-2-酮，3包括3-乙基衍生物1，4是合成吲哚生物碱的已知中间体。以前合成吲哚并[2，3-o]喹嗪-2-酮环系的方法包括在合成的关键步骤中通过形成C12 a-C12 b键5闭合环C或构建环D 6。在我们关于使用2-芳基-4-哌啶酮作为合成中间体的研究的背景下，7我们在此报道了吲哚并[2，3-a]喹嗪-2-酮系统的新合成条目，该合成条目基于在关键合成步骤中通过使用适当取代的2-（2-吲哚基）-4-哌啶酮衍生物在吲哚3-位上环化来制备环C。[8]通过类似的策略，我们最近发现了一种新的苯并[o]喹嗪-2-酮的合成方法，它构成了生物碱eme-tine的形式合成。
A new route to the indolo [2, 3-o] quinolizidin-2-one ring system is reported. It is based on the elaboration of the C ring in the key step by cyclization upon the indole 3-position of an N-substituted 2-(2-mdolyl)-4-piperidone derivative. This cyclization was efficiently accomplished by treatment of the sulfonylated indole alcohol 6 with potassium ferf-butoxide.The indolo [2, 3-o] quinolizidine ring system has received great attention from a synthetic standpoint because it is present in a large number of indole alkaloids. 2 In par-ticular, the indolo [2, 3-a] quinolizidin-2-ones, 3 including the 3-ethyl derivative l, 4 are known intermediates in the synthesis of indole alkaloids. Previous approaches to the indolo [2, 3-o] quinolizidin-2-one ring system involveeither closure of ring C by formation of the C12a-C12b bond5 or construction of ring D6 in the key steps of the synthesis. In the context of our studies about the use of 2-aryl-4-piperidones as synthetic intermediates, 7 we report here a new synthetic entry to the indolo [2, 3-a] quinolizidin-2-one system based on the elaboration of ring C in the crucial synthetic step by cyclization upon the indole 3-position using an appropriately substituted 2-(2-indolyl)-4-piperidone derivative. 8 By a similar strategy, we recently reported70 a new synthesis of benzo [o] quinolizidin-2-ones which constitutes a formal synthesis of the alkaloid eme-tine.