Intramolecular Diels–Alder reactions of oxazole–olefins: synthesis of the Rauwolfia alkaloids suaveoline and norsuaveoline
作者:Masashi Ohba、Itaru Natsutani、Takashi Sakuma
DOI:10.1016/j.tet.2007.07.070
日期:2007.10
A full account of the highly stereoselective total synthesis of two indole alkaloids, suaveoline (4) and norsuaveoline (5), is presented. Central features of the synthetic strategy include the conversion of l-tryptophan methyl ester (12) into the oxazole derivative 11 and the intramolecular Diels–Alder reaction of the oxazole–olefin 19 leading to the pentacyclic pyridine derivative 21.
介绍了两个吲哚生物碱,suaveoline(4)和norsuaveoline(5)的高度立体选择性总合成的完整说明。合成策略的主要特征包括将L-色氨酸甲酯(12)转化为恶唑衍生物11和恶唑-烯烃19的分子内Diels-Alder反应,生成五环吡啶衍生物21。