Construction of the Tricyclic Furanochroman Skeleton of Phomactin A via the Prins/Conia-Ene Cascade Cyclization Approach
Construction of the Tricyclic Furanochroman Skeleton of Phomactin A via the Prins/Conia-Ene Cascade Cyclization Approach
复制标题
通过 Prins/Conia-Ene 级联环化方法构建 Phomactin A 的三环呋喃色满骨架
DOI：
10.1021/jo200644t
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发表时间：
2011-08-19
影响因子：
3.6
通讯作者：
Lee, Chi-Sing
中科院分区：
文献类型：
--
作者：
Huang, Shuangping;Du, Guangyan;Lee, Chi-Sing
在乙腈中，In（OTf）（3）在0 ~ 70 ℃进行了底物控制的不对称Prins/Conia烯级联环化反应.这些条件在一锅中提供了非常好的1-氧杂萘烷产物产率，并且有效地抑制了1-氧杂萘烷产物的外消旋化，几乎没有对映体过量（ee）损失。该级联环化反应已成功地用于以无环β-酮酯和炔醛作为底物通过一锅操作（66%产率，单一非对映异构体）构建phomactin A的高度官能化的1-oxadecalin单元。通过环氧化/脱烷氧基羰基化反应，在温和的条件下，1-氧萘烷部分可以很容易地转化为三环呋喃并色满骨架，三步收率为52%。
A substrate-controlled asymmetric Prins/Conia-ene cascade cyclization has been developed with In(OTf)(3) in CH3CN from 0 to 70 degrees C. These Conditions afforded very good yields of the 1-oxadecalin product in one pot and effectively suppressed the racemization of the 1-oxadecalin product with almost no enantiomeric excess (ee) loss. This cascade cyclization has been successfully employed for the construction of the highly functionalized 1-oxadecalin unit of phomactin A with an acyclic beta-keto ester and an alkynal as the substrates via a one-pot operation (66% yield, single diastereomer). The 1-oxadecalin moiety has been readily converted to the tricyclic furanochroman skeleton of phomactin A via the epoxidation/dealkoxycarbonylation protocol under very mild conditions with 52% yield in three steps.