Synthetic studies on Sch 202596, an antagonist of the galanin receptor subtype GalR1: an efficient synthesis of (±)-geodin, the spirocoumaranone part of Sch 202596
作者:Tadashi Katoh、Osamu Ohmori、Katsuhiko Iwasaki、Munenori Inoue
DOI:10.1016/s0040-4020(01)01250-9
日期:2002.2
corresponding to the spirocoumaranone part of Sch 202596 (1) was accomplished in a convergent manner. The synthetic method features (i) a coupling reaction of the aryl aldehyde 6 with the aryl lithium 7 generated in situ from the aryl bromide 8 to deliver the highly substituted diaryl methanol 24 (6+7→24) and ii) oxidative spirocyclization reaction of the benzophenone 4 to construct the requisite spirocoumaranone
以收敛的方式完成了与Sch 202596(1)的螺香古兰烷酮部分相对应的(±)-geodin [(±)-2 ]的高效合成。该合成方法的特征在于(i)芳基醛6与由芳基溴化物8原位产生的芳基锂7的偶联反应,以递送高度取代的二芳基甲醇24(6 + 7 → 24),以及ii)氧化的螺环化反应。二苯甲酮4构筑必要的螺香豆香烷骨架[ 4 →(±)-2 ]为关键步骤。芳香段图6和图8分别由可商购的3,5-二羟基苯甲酸甲酯(9)和5-甲基间苯二酚(10)制备。