Synthesis ofAristotelia-Type Alkaloids. Part VIBiomimetic Synthesis of (+)-Aristofruticosine
作者:Ren� Beerli、Hans-J�rg Borschberg
DOI:10.1002/hlca.19910740113
日期:1991.1.30
indole moiety via an intramolecular, allylic nucleophilic displacement reaction. Subsequent reductive removal of the protecting group completed the first synthesis of the Aristotelia alkaloid (+)-aristofruticosine ((+)-4). This straightforward synthesis confirmed the tentative structure (+)-4, proposed by Bick and Hai, and established the hitherto unknown absolute configuration of this metabolite.
(S)-紫苏醇(5)经五步转化为(S)-7-(苯硫基)-p-薄荷基-1-en-8-胺(11)。该结构单元与1-(4-甲氧基苯基磺酰基)-1 H-吲哚-3-乙醛(12)的缩合产生预期的亚胺15,该亚胺15在暴露于无水乙醇中以54%的产率环化成受保护的20-(苯硫基)氨甲tine呤16。碳酸氢钠 用烷基化试剂处理该中间体导致经由吲哚部分保护的(+)-马兜铃果糖碱分子内烯丙基亲核取代反应。随后的还原除去保护基团的完成了的第一合成Aristotelia生物碱(+) - aristofruticosine((+) - 4)。这种简单的合成方法证实了Bick和Hai提出的暂定结构(+)- 4,并建立了该代谢物迄今未知的绝对构型。