描述了一种用于软海绵素 B 全合成的新策略,其特点是通过先形成 C-O 键,然后形成 C-C 键,从经典方法中逆转了许多环醚的顺序构建。利用尼古拉斯反应生成线性醚作为软海绵素 B 和软海绵素和艾日布林化合物家族其他成员全合成的前体,这种新方法为开发这些复杂且有价值的化合物的改进合成提供了新的机会。在本文中,我们报告了已定义片段I、MN、EFG和A的合成。片段I和MN然后将其偶联并细化为高级中间体IJKLMN,其与片段EFG结合,在适当的细化和大环内酯化后,提供更高级的多环中间体EFGHIJKLMN。后者的精心制作和与片段A 的偶联,然后进一步功能化,通过短而收敛的途径完成了软海绵素 B 的全合成。
A concise and convergent route for the stereoselective total synthesis of cytotoxic macrolides pestalotioprolides G and H has been developed for the first time. Intramolecular Heck coupling has been chosen to cyclize the 14-membered macrocycle. This synthetic study strongly suggests that the proposed structure of pestalotioprolide H may need to be corrected as the spectroscopic data on the synthesized
Synthesis of symmetric HIJ-ring model of ciguatoxin
作者:Akihito Nonoyama、Akinari Hamajima、Minoru Isobe
DOI:10.1016/j.tet.2007.03.012
日期:2007.6
addition to form a symmetric eight-membered ether-ketone with syn/trans stereochemistry in selective manner. The corresponding vinyl triflate of this ketone was allowed to convert to the vinyl methyl derivative via cross-coupling reaction. This endo-olefinic tetrahydro-2H-oxocin was selectively reduced to afford α-methyl product. The corresponding exo-olefinic oxocane derivative, on the other hand
chemo- and stereoselective method for the synthesis of (E)-2-silyl-1,3-butadienes from a broad range of allenols using mild Si–B reagents is reported in this study. Our protocol required a short reaction time at ambient temperature to produce the desired dienes in high yields. Synthetic applications are highlighted by the one-potsynthesis of tetrasubstituted arylsilanes from allenols as well as the
本研究报道了一种铜催化化学和立体选择性方法,使用温和的 Si-B 试剂从多种联烯醇合成 ( E )-2-甲硅烷基-1,3-丁二烯。我们的方案需要在环境温度下进行短反应时间才能以高产率产生所需的二烯。从联烯醇一锅合成四取代芳基硅烷以及 C-Si 键的进一步功能化突出了合成应用。