Total synthesis of an enantiomeric pair of FR900482. 3. Completion of the synthesis by assembling the two segments
作者:Tadashi Katoh、Yuriko Nagata、Toshiharu Yoshino、Shogo Nakatani、Shiro Terashima
DOI:10.1016/s0040-4020(97)00652-2
日期:1997.7
formation of the N-hydroxylamino ketone 25 in situ generated from the ketone 24 to construct the requisite tetracyclic ring system 26 (24→25→26) as the key steps. The in vitro cytotoxicity assay of the synthesized compounds (1, ent-1, 31, ent-31, 32, and ent-32) against P388 murine leukemia cells disclosed that FR900482 (1) and its congeners 31, 32 bearing natural absolute configuration are 100 times more
通过以下方法完成标题合成:(i)将芳族链段2与对映体纯的脂族链段3偶联以安装必要的碳单元(2 + 3→4 );(ii)高度官能化的二醛10的分子内醛醇缩合反应,以形成所需的八元环系统12(10→12 );(iii)在羟基酮15的C-8位差向异构化以获得正确的立体化学(15→16 );(iv)由酮24原位产生的N-羟基氨基酮25的内部半缩醛形成,以构建必要的四环体系26(24→25→26 )作为关键步骤。合成的化合物的体外细胞毒性测定(1,ent- 1,31,ent- 31,32,和ent- 32)对P388鼠白血病细胞公开了FR900482(1)和它的同系物31,32轴承天然绝对构具有比相应的非天然对映异构体(ent- 1,ent- 31,ent- 32)高100倍的细胞毒性。