Studies for the synthesis of xenicane diterpenes. A stereocontrolled total synthesis of 4-hydroxydictyolactone.
Studies for the synthesis of xenicane diterpenes. A stereocontrolled total synthesis of 4-hydroxydictyolactone.
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Xenicane二萜的合成研究。
DOI：
10.1021/ja902677t
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发表时间：
2009
影响因子：
15
通讯作者：
Miller,NathanA
中科院分区：
文献类型：
--
作者：
Williams,DavidR;Walsh,MartinJ;Miller,NathanA
描述了天然产物 xenicane 二萜家族成员 4-羟基二酰内酯 (4) 的立体控制全合成。这些研究的特点是开发了 B-烷基 Suzuki 交叉偶联反应，用于从无环前体直接获得 (E)-环壬烯。爱尔兰-克莱森重排被有效地利用来建立 4 的连续 C2、C3、C10 立体三联体的主链不对称性。该合成策略设计了甲酸酯的分子内Nozaki-Hiyama还原烯丙基化，用于立体选择性形成五元乳醇22。此外，描述了使用联烯基溴化镁进行内部定向 SE' 炔丙基化，以建立 C4 醇 in27 的立体化学，并且末端炔烃随后通过区域选择性顺-甲硅烷基甲锡烷基化进行官能化以产生 30。最后，衍生自 43 的酯烯醇化物的立体控制苯基硒化导致所需的顺式氧化消除，产生天然产物 4。
The stereocontrolled total synthesis of 4-hydroxydictyolactone (4), a member of the xenicane diterpene family of natural products, is described. These studies feature the development of the B-alkyl Suzuki cross-coupling reaction for direct access to (E)-cyclononenes from acyclic precursors. The Ireland−Claisen rearrangement is effectively utilized to establish the backbone asymmetry of the contiguous C2, C3, C10stereotriad of4. The synthesis strategy has devised an intramolecular Nozaki−Hiyama reductive allylation of a formate ester for the stereoselective formation of five-membered lactols22. In addition, an internally directed SE′ propargylation using allenylmagnesium bromide is described to establish the stereochemistry of the C4alcohol in27, and the terminal alkyne is subsequently functionalized via a regioselectivesyn-silylstannylation to yield30. Finally, the stereocontrolled phenylselenylation of the ester enolate derived from43leads to the desiredsyn-oxidative elimination to yield the natural product4.