Synthesis of (+)-conagenin
Synthesis of (+)-conagenin
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DOI：
10.1021/jo050407s
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发表时间：
2005-06-24
影响因子：
3.6
通讯作者：
Ichikawa, Y
中科院分区：
文献类型：
--
作者：
Matsukawa, Y;Isobe, M;Ichikawa, Y
实现了 (+)-conagenin 的有效全合成。使用氰酸烯丙酯至异氰酸酯重排合成了刀豆蛋白的右侧片段，即含有连接至氮的四元立构中心的α-甲基丝氨酸。左侧片段 2,4-二羟基-3-甲基戊酸具有三个连续的立体中心，该中心是通过 Cossy 报道的 2-烷基-1,3-二酮的对映选择性单还原和 β-羟基酮的螯合控制立体选择性还原而有效构建的。这两个片段通过分子内酰胺键形成高效偶联。
An efficient total synthesis of (+)-conagenin was achieved. The right fragment of conagenin, α-methylserine containing a quaternary stereocenter attached to nitrogen, was synthesized using allyl cyanate-to-isocyanate rearrangement. The left fragment, 2,4-dihydroxy-3-methylpentanoic acid, has three contiguous stereogenic centers, which was efficiently constructed by enantioselective monoreduction of 2-alkyl-1,3-diketones reported by Cossy, and chelation-controlled stereoselective reduction of β-hydroxy ketone. These two fragments were coupled through intramolecular amide bond formation with high efficiency.