base-mediated intramolecular Diels–Alder cycloadditions of tryptamine-derived Zincke aldehydes is described. This important complexity-generating transformation provides the tetracyclic core of many indole monoterpene alkaloids in only three steps from commercially available starting materials and played a key role in short syntheses of norfluorocurarine (five steps), dehydrodesacetylretuline (six steps), valparicine
描述了由
色胺衍生的
锌醛的碱基介导的分子内Diels-Alder环加成反应的完整过程。这项重要的复杂性转化过程可从市售起始原料仅三步即可提供许多
吲哚单萜
生物碱的四环核,并且在正
氟尿
嘧啶的短合成(五步),脱氢脱乙酰基
苯甲酸(六步),瓦尔帕比星(七步)的短合成中发挥了关键作用。 ,和
士的宁(六个步骤)。还讨论了该反应的合理机理可能性,产物令人惊讶地容易的二聚化,以及在特定条件下出乎意料的环还原以再生
锌酮醛。