Enol ester as an olefinic partner in enyne cyclization. A novel tandem cyclization to stereodefined bicyclo[3.3.0]octenes.
Enol ester as an olefinic partner in enyne cyclization. A novel tandem cyclization to stereodefined bicyclo[3.3.0]octenes.
复制标题
DOI：
10.1002/chin.200331041
复制
发表时间：
2003-04
影响因子：
15
通讯作者：
H. Urabe;D. Suzuki;Misa Sasaki;F. Sato
中科院分区：
文献类型：
--
作者：
H. Urabe;D. Suzuki;Misa Sasaki;F. Sato
当(Z)-1-三十二-6-炔基丙酸酯用钛（II）烷氧试剂Ti(O-i-Pr)4/2 - prmgcl处理时，发生了一种新的连续环化反应，在水处理后得到(1RS,2RS,3SR)-3-乙基-4-己基-4-双环[3.3.0]辛烯-2,3-二醇，几乎是一个立体异构体。这种环化的普遍性也得到了证明。同样，(Z)-3-丁基-1-三十二-6-炔基丙酸酯(1RS,2RS,3SR,8SR)-8-丁基-3-乙基-4-己基-4-双环辛烯-2,3-二醇具有bbb95:5的非对映选择性，表明产物中同时构建了四个连续的立体中心，几乎具有完全的非对映选择性。
When (Z)-1-tridecen-6-ynyl propanoate was treated with a titanium(II) alkoxide reagent, Ti(O-i-Pr)4/2i-PrMgCl, a novel tandem cyclization took place to give (1RS,2RS,3SR)-3-ethyl-4-hexyl-4-bicyclo[3.3.0]octene-2,3-diol virtually as a single stereoisomer after aqueous workup. The generality of this cyclization was also shown. Similarly, (Z)-3-butyl-1-tridecen-6-ynyl propanoate afforded (1RS,2RS,3SR,8SR)-8-butyl-3-ethyl-4-hexyl-4-bicyclo[3.3.0]octene-2,3-diol with a diastereoselectivity of >95:5, demonstrating the simultaneous construction of a total of four consecutive stereogenic centers in the product and with virtually complete diastereoselectivity.