A model study on installation of (Z)-γ-methylglutaconic acid onto the 3-aminophenol core of divergolide A
作者:Guanglian Zhao、Jinlong Wu、Wei-Min Dai
DOI:10.1016/j.tet.2015.05.052
日期:2015.7
hydroquinone core, which is biosynthetically transformed from an aromatic starter unit, 3-amino-5-hydroxybenzoic acid (AHBA). The macrocyclic ring of divergolide A and F is assembled by linking the amido hydroquinone unit with the polyketide backbone through (Z)-γ-methylglutaconic acid as the tether while (E)-γ-methylglutaconic acid is found in divergolide E, G, and H. A model study has been conducted for installation
Divergolide A及其四个同类物divergolide E–H具有酰胺取代的对苯二酚核心,该核心是由芳族起始剂3-氨基-5-羟基苯甲酸(AHBA)进行生物合成的。曲高屈内酯A和F的大环是通过(Z)-γ-甲基戊二酸作为束缚链将酰胺基对苯二酚单元与聚酮化合物骨架连接而组装而成的,而在曲高屈内酯E,G和C中发现了(E)-γ-甲基戊二酸。 H.已经进行了模型研究,通过两种方法将(Z)-γ-甲基戊二酸安装在曲高立德A的3-氨基苯酚核心上:(a)CuI–MeNHCH 2 CH 2 NHMe催化的甲基化酰胺化(Z)-4-氨基甲酰基-2-甲基丁-2-烯酸酯与芳基溴化物;(b)(Z)-γ-甲基谷氨酸酐与苯胺衍生物的区域选择性氨解。观察到在CuI催化条件下(Z)-构型的异构化主要产生(E)-产物,而仅在氨解条件下获得(Z)-产物。这些结果可能对水曲柳内酯A和E–H的全合成有用。