Stereoselective formal synthesis of (+)-allokainic acid via thiol-mediated acyl radical cyclization.
Stereoselective formal synthesis of (+)-allokainic acid via thiol-mediated acyl radical cyclization.
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DOI：
10.1248/cpb.58.1511
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发表时间：
2010-11
影响因子：
1.7
通讯作者：
Ken‐ichi Yamada;Tomohiro Sato;Masaki Hosoi;Y. Yamamoto;K. Tomioka
中科院分区：
文献类型：
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作者：
Ken‐ichi Yamada;Tomohiro Sato;Masaki Hosoi;Y. Yamamoto;K. Tomioka
以L-谷氨酸为起始原料，通过巯基介导的酰基自由基环化反应，立体选择性地合成了（+）-别红藻氨酸。甲酰基烯酸酯的环化以高度非对映选择性的方式进行，得到反式-4，5-二取代的吡咯烷-3-酮，而不产生顺式异构体。然后通过铁催化的偶联反应将吡咯烷酮转化为（+）-别红藻氨酸的合成中间体。
Stereoselective formal synthesis of (+)-allokainic acid was accomplished starting from L-glutamate by using a thiol-mediated acyl radical cyclization as a key step. The cyclization of a formylalkenoate proceeded in a highly diastereoselective manner to give trans-4,5-disubstituted pyrrolidin-3-one without the production of the cis-isomer. The pyrrolidinone was then converted into the established synthetic intermediate of (+)-allokainic acid via the iron-catalyzed coupling reaction with an isopropenyl Grignard reagent.