New [3 + 4] Annulation. Reactions of (.beta.-(Trimethylsilyl)acryloyl)silanes with the Lithium Enolates of .alpha.,.beta.-Unsaturated Methyl Ketones
New [3 + 4] Annulation. Reactions of (.beta.-(Trimethylsilyl)acryloyl)silanes with the Lithium Enolates of .alpha.,.beta.-Unsaturated Methyl Ketones
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新 [3 4] 废止。
DOI：
10.1021/ja00128a047
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发表时间：
1995
影响因子：
15
通讯作者：
E. Yoshii
中科院分区：
文献类型：
--
作者：
K. Takeda;M. Takeda;A. Nakajima;E. Yoshii
我们最近报道了一个新的[3+ 2]环化反应，该反应涉及（/3-（苯基硫）丙烯酰）硅烷和2-烷酮烯醇化锂（由LDA生成）生成1-烷基-2-（苯基硫）-4-（硅氧基）-3-戊烯-1-醇。1我们现在描述了一个高效的[3+ 4]环化反应的发现，2这是通过使用(£>（yS-（三甲基-酰基硅基）丙烯酰）-ferí-butyldimethylsilane (l) 3与，/3-不饱和甲基酮烯醇酯2结合作为四碳组分来实现的，以一种简单的方式提供了新颖的，高度功能化的环庚烯酮3（方案1）。我们首先研究了（£）- 1与无环，ß-不饱和甲基酮在上述[3+ 2]环化的相同条件下的反应。因此，将3-庚烯-2-one的烯酸锂（在THF - 80℃下由LDA生成）加入到(E)-1 - 80℃的THF溶液中，并将混合物（0.02 M）加热至30℃，持续1小时，得到cu -6-丙基-5-（三甲基硅基）-3-环庚烯酮（3a）作为唯一可检测的立体异构体4，硅胶层析后收率为73%（表1，进入）
We have recently reported a new [3+ 2] annulation reaction, which involves the reaction of (/3-(phenylthio) acryloyl) silane and lithium enolates of 2-alkanones (generated with LDA) to afford 1-alkyl-2-(phenylthio)-4-(silyloxy)-3-penten-1-ol. 1 We now describe the discovery of an efficient [3+ 4] annulation reaction, 2 which has been achieved by using (£>(yS-(trimeth-ylsilyl) acryloyl)-ferí-butyldimethylsilane (l) 3 in combination with,/3-unsaturated methyl ketone enolates 2 as the four-carbon components, affording novel, highly functionalized cyclohep-tenones 3 in a straightforward manner(Scheme 1). We first investigated the reaction of (£)-l with acyclic, ß-unsaturated methyl ketones under the same conditions as employed in the aforementioned [3+ 2] annulation. Thus, the lithium enolate of 3-hepten-2-one (generated with LDA in THF at—80 C) was added to a THF solution of (E)-1 at—80 C, and the mixture (0.02 M) was allowed to warm to—30 C over a period of 1 h to afford cw-6-propyl-5-(trimethylsilyl)-3-cycloheptenone (3a) as the only detectablestereoisomer4 and in 73% yield after silica gel chromatography (Table 1, entry