An enantioselective synthesis of tarchonanthuslactone
An enantioselective synthesis of tarchonanthuslactone
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DOI：
10.1021/jo0163400
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发表时间：
2002-04-19
影响因子：
3.6
通讯作者：
O'Doherty, GA
中科院分区：
文献类型：
--
作者：
Garaas, SD;Hunter, TJ;O'Doherty, GA
以山梨酸乙酯为起始原料，经八步反应实现了对映选择性合成蒲公英内酯。该路线的不对称性通过Sharpless不对称二羟基化引入，允许获得任一对映异构体。该合成利用钯催化还原和非对映选择性碱催化缩醛形成作为关键步骤。通过Still-烯化/内酯化序列建立了焦南花内酯的吡喃环。DCC介导的二氢咖啡酸的连接完成了以19%的总收率的tarchonanthuslactone的合成。
An enantioselective synthesis of tarchonanthuslactone has been achieved in eight steps from ethyl sorbate. The asymmetry of the route was introduced via a Sharpless asymmetric dihydroxylation allowing access to either enantiomer. The synthesis utilizes a palladium-catalyzed reduction and a diastereoselective base-catalyzed acetal formation as the key steps. The pyran ring of tarchonanthuslactone was established by a Still-olefination/lactonization sequence. DCC-mediated attachment of dihydrocaffeic acid completed the synthesis of tarchonanthuslactone in a 19% overall yield.