Synthetic studies on the icetexones: enantioselective formal syntheses of icetexone and epi-icetexone.
Synthetic studies on the icetexones: enantioselective formal syntheses of icetexone and epi-icetexone.
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DOI：
10.1016/j.tet.2013.04.049
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发表时间：
2013-07-08
期刊：
影响因子：
2.1
通讯作者：
Sarpong, Richmond
中科院分区：
文献类型：
--
作者：
Cortez, Felipe de Jesus;Lapointe, David;Hamlin, Amy M.;Simmons, Eric M.;Sarpong, Richmond
关键词：
已经探索了两种合成icetexane二萜icetexone和epi-icetexone的策略，这两种策略依赖于Ga(III)催化的炔基茚底物的环异构化以产生稠合的[6-7-6]三环化合物。在第一种方法中，获得带有偕二甲基基团的三环化合物，为探索靠近羟基导向基团的一个甲基的C-H官能化铺平了道路。这种方法最终没有成功，只得到了环裂产物。在第二种方法中，使用带有氰基取代基的炔基茚底物，这有效地提供了访问二萜类的icetexone亚类的功能手柄。利用关键的环氧化物开环/二氮烯重排序列来完成icetexone和epi-icetexone的正式合成，对此进行了详细讨论。此外，使用Rh催化的共轭加成反应制备了对映体富集形式的含氰基底物，这为这些天然产物的对映选择性合成提供了一条途径。
Two strategies for the synthesis of the icetexane diterpenoids icetexone and epi-icetexone that rely on Ga(III)-catalyzed cycloisomerization of alkynyl indene substrates to yield fused [6-7-6] tricycles have been explored. In the first approach, access to a tricycle bearing a gem-dimethyl group paved the way for explorations of C–H functionalization of one of the methyl groups in close proximity to a hydroxyl-directing group. This approach was ultimately unsuccessful and led only to ring cleaved products. In the second approach, an alkynyl indene substrate bearing a cyano substituent was utilized, which was effective in providing a functional handle to access the icetexone subclass of diterpenoids. A key epoxide opening/diazene rearrangement sequence was utilized to complete a formal synthesis of icetexone and epi-icetexone, which is discussed in detail. Furthermore, the cyano-containing substrate has been prepared in enantioenriched form using a Rh-catalyzed conjugate addition reaction, which now provides a route to the enantioselective synthesis of these natural products.
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影响因子：
5.2
作者：
Simmons, Eric M.;Sarpong, Richmond
通讯作者：
Sarpong, Richmond
DOI：
10.1039/p29760001728
发表时间：
1976-01-01
期刊：
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
影响因子：
--
作者：
TAIRA, Z;WATSON, WH;DOMINGUEZ, XA
通讯作者：
DOMINGUEZ, XA
影响因子：
5.2
作者：
Simmons, Eric M.;Yen, Jennifer R.;Sarpong, Richmond
通讯作者：
Sarpong, Richmond
影响因子：
--
作者：
SAWAMURA, M;HAMASHIMA, H;ITO, Y
通讯作者：
ITO, Y
影响因子：
5.2
作者：
Yu, JQ;Corey, EJ
通讯作者：
Corey, EJ