An enantioselective synthesis of rhizoxin D (2), isolated from the plant pathogenic fungus Rhizopus chinensis, is described. The overall strategy is based on elaboration of the δ-lactone-substituted vinyl stannane 7 and the phosphonate-substituted vinyl iodide 9, followed by their coupling to the core 16-membered macrolide 6via a sequential intermolecular Horner–Wadsworth–Emmons olefination, leading to 50, and by an intramolecular Stille reaction. The triene oxazole-containing side chain in rhizoxin D is then introduced using the phosphine oxide 8 in an E-selective Horner–Wittig reaction with the macrolide aldehyde 51b.
描述了一种从植物病原真菌中国根霉中分离得到的利佐辛D(2)的对映选择性合成方法。整体策略基于对δ-内酯取代的
乙烯锡7和
磷酸酯取代的
乙烯碘9的精细加工,随后通过一系列分子间Horner-Wadsworth-Emmons烯化反应与核心的16元大环内酯6耦合,生成50,并通过分子内Stille反应完成。利佐辛D中的
三烯并
噁唑侧链随后利用
磷氧化物8在大环内酯醛51b上的E选择性Horner-Wittig反应引入。