作者:J.S. Yadav、Sipak Joyasawal、S.K. Dutta、A.C. Kunwar
DOI:10.1016/j.tetlet.2007.05.021
日期:2007.7
A stereoselective synthesis of the ABCD ring framework of azaspiracid-1 and azaspiracid-3 has been achieved using a tandem bis-spiroketalization protocol in the presence of a mild proton source from 1,4-diketone precursor. A tetrahydrofuran intermediate with the correct stereochemistry for the D ring of azaspiracids-1 and 3 was then taken through a linear sequence of reactions to afford the desired
在存在来自1,4-二酮前体的温和质子源的条件下,使用串联双螺缩酮化方案已实现了azaspiracid-1和azaspiracid-3 ABCD环骨架的立体选择性合成。然后,通过线性反应序列,对氮杂螺环酸-1和3的D环具有正确的立体化学的四氢呋喃中间体,得到所需的二酮前体。然后,通过使用Sharpless不对称二羟基化反应,然后使用均烯丙基衍生物进行醚化,来构建azaspiracid-1的D环。通过广泛的NMR分析,建立了具有四个连续环的ABCD环骨架的结构。