Site selectivity of the Diels-Alder reactions of 3-[1-(tert-butyldimethylsilyloxy)vin-1-yl]furan and 3-(propen-2-yl)furan. Synthesis of 4-substituted benzofurans
Site selectivity of the Diels-Alder reactions of 3-[1-(tert-butyldimethylsilyloxy)vin-1-yl]furan and 3-(propen-2-yl)furan. Synthesis of 4-substituted benzofurans
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DOI：
10.1021/jo951546k
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发表时间：
1996-02-23
影响因子：
3.6
通讯作者：
Muchowski, JM
中科院分区：
文献类型：
--
作者：
Benitez, A;Herrera, FR;Muchowski, JM
5-乙烯基呋喃 5 和 27 与 DMAD、N-苯基马来酰亚胺和马来酸二甲酯的 Diels-Alder 反应提供了源自呋喃环二烯体系（环内加成）和呋喃 2,3-双键 3-乙烯基二烯体系（环外加成）的加成产物。例如，化合物6和7是由5和DMAD获得的。相反，含有苯基亚磺酰基的亲二烯体，例如19-21，产生的产物完全来自环外反应模式。这些产物是4-取代苯并呋喃、特别是4-羟基苯并呋喃的有用前体。
The Diels-Alder reaction of 5-vinylfurans 5 and 27 with DMAD, N-phenylmaleimide, and dimethyl maleate afforded products derived both from addition to the furan ring diene system (intraannular addition) and to the furan 2,3-double bond 3-vinyl group diene system (extraannular addition). For example, compounds 6 and 7 were obtained from 5 and DMAD. In contrast, dienophiles containing a phenylsulfinyl group, such as 19-21, gave products derived exclusively from the extraannular reaction mode. These products are useful precursors of 4-substituted benzofurans, especially 4-hydroxybenzofurans.