First asymmetric synthesis of a differentially silyl-protected tris(alkynyl)methyl methyl ether
作者:Vito Convertino、Peter Manini、W. Bernd Schweizer、François Diederich
DOI:10.1039/b601380e
日期:——
For an improved synthesis of the recently described expanded octamethoxycubane with a central C56 core, formally obtained by inserting buta-1,3-diynediyl moieties into all C(sp3)–C(sp3) bonds of octamethoxycubane, the preparation of the optically pure methyl ether of a differentially silyl-protected trispropargylic alcohol was required. The key step of the preparation involved a diastereoselective addition of a lithium acetylide to an optically active alkynyl ketone under Cram chelation control.
为了改进最近描述的具有中央 C56 核心的扩展八甲氧基环己烷的合成,需要制备不同硅烷保护的三丙炔醇的光学纯甲基醚,这种醚是通过在八甲氧基环己烷的所有 C(sp3)-C(sp3) 键中插入丁-1,3-二炔基而正式获得的。制备的关键步骤是在克拉姆螯合控制下,将乙酰化锂与光学活性炔基酮进行非对映选择性加成。