Stereodivergent synthesis of jaspine B and its isomers using a carbohydrate-derived alkoxyallene as C<sub>3</sub>-building block
作者:Volker Martin Schmiedel、Stefano Stefani、Hans-Ulrich Reissig
DOI:10.3762/bjoc.9.291
日期:——
Herein we present the synthesis of the anhydrophytosphingosine jaspine B and three of its stereoisomers using a carbohydrate-derived alkoxyallene in order to obtain the products in enantiopure form. Key step of the reaction sequence is the addition of the lithiated alkoxyallene to pentadecanal, setting the configuration at the later C-2 of the ring system. This reaction step proceeds with moderate
在此,我们介绍了使用碳水化合物衍生的烷氧基丙二烯合成脱水植物鞘氨醇 jaspine B 及其三种立体异构体,以获得对映体纯形式的产物。反应序列的关键步骤是将锂化的烷氧基丙二烯加成到十五烷醛,在环系统的后面 C-2 处设置构型。该反应步骤以中等选择性进行,因此导致对天然产物及其对映体的立体发散方法。金催化的 5-内环化得到相应的二氢呋喃,经过分离、烯醇醚部分的叠氮化和两个随后的还原步骤,得到天然产物及其立体异构体。
Synthesis of Pachastrissamine from Phytosphingosine: A Comparison of Cyclic Sulfate vs an Epoxide Intermediate in Cyclization
作者:Taeho Lee、Sukjin Lee、Young Shin Kwak、Deukjoon Kim、Sanghee Kim
DOI:10.1021/ol062756u
日期:2007.2.1
[reaction: see text] The syntheses of the cytotoxic natural product pachastrissamine and its unnatural 4-epi-congener were accomplished starting from a natural phytosphingosine. The relatively unstrained cyclicsulfate intermediate smoothly underwent the 5-endo cyclization to yield the 2,3,4-trisubstituted tetrahydrofuran ring system of pachastrissamine. The corresponding epoxy alcohol afforded the