【作者】 林静；

【导师】 卿凤翎；

【作者基本信息】 东华大学 ， 纺织化学与染整工程， 2010， 博士

【摘要】 目前,大约一半以上的药物来自天然产物或对其结构进行改造而得到的类似物,因此对天然产物的研究成为发现新药的重要途径。大量的事实表明,将氟原子或含氟基团选择性地引入有机分子能显著地改变原有分子的生理活性,从而被广泛地应用于药物设计中。近年来,向具有重要生物活性的天然产物引入含氟基团已经引起科学家的广泛关注。众所周知,α,β-不饱和δ-内酯环是天然产物中广泛存在的重要的活性结构。本文尝试从廉价易得的原料出发合成了几类具有潜在生物活性的含二氟亚甲基α,β-不饱和6-内酯结构的天然产物类似物,期望发现高活性低毒副作用的新化合物。本论文主要分为以下两个部分：第一部分：对具有优异的生物活性的天然内酯Pironetin的二氟亚甲基取代类似物79进行了全合成的研究初探。尝试了多条路线,经过一系列条件的摸索,成功地合成了两个片段3和30,然而对这两个片段的连接遇到了困难,迫使我们不得不改变合成策略。由1,3-丙二醇出发,经两次Evans类型的不对称Aldol反应构建分子中相邻的四个手性中心,由高产率的Wittig反应来引入分子中的双键,然后醛67,68与含氟砌块10进行炔丙基化反应得到69和70,顺式还原化合物69,70的三键,选择性脱除二甲基叔丁基硅保护基,氧化1,5-二醇同时关环构建内酯环,成功地完成了含二氟亚甲基Pironetin类似物的全合成,并对得到的四个类似物79,80,81,82进行了生物活性测试。第二部分：由廉价易得的D-葡萄糖酸δ-内酯出发,经过一系列地转化得到醛90,醛90与含氟砌块10反应得到关键的中间体91和92,然后再经多步转化得到两个全部去乙酰基的二氟亚甲基Boronolide类似物99,100以及两个二氟亚甲基Boronolide类似物101和102。同时以上述合成中的中间体87为起始原料,我们也合成了具有潜在生物活性的天然产物Anamarine的二氟亚甲基取代类似物133和134。其中由Horner-Wadsworth-Emmons成烯反应构建分子中的反式双键,由1,5-二醇氧化关环构建内酯环。更多还原

【Abstract】 Currently more than half of the prescription drugs derive from natural products, or natural product analogues. Therefore, the natural product-inspired drug discovery and development has become one of the most efficient strategies to explore new drugs in recent years. It’s well known that fluorinated compounds play an important role in life sciences due to the introduction of one or a few fluorine atoms into an organic compound showing profound changes in its chemical and biological nature, so the interest of fluorinated analogues of natural products is increasing continuously. As we known,α,β-unsaturatedδ-lactone is a common structural unit of natural products with medicinal interest. In this dissertation, we designed and synthesized some potentially bioactive gem-difluoromethylenated natural products withα,β-unsaturated 8-lactones from readily available materials in the hope of exploring a new compound, which shows excellent bioactivity and lower toxicity. The dissertation is divided into following two parts:Part I:Gem-difluoromethylenated analogues of Pironetin, which exhibits significant activity were syntheiszed. Firstly two key segments 3 and 30 have been synthesized after several trials. However, the coupling of the two segments was unsuccessful, which made us adjust our synthetic strategy. The straightforward synthesis of four gem-difluoromethylenated analogues of Pironetin 79,80,81,82 began with available 1,3-propanediol. This approach included the use of two efficient Evans oxazolidinone-mediated syn-aldol condensations to establish the four contiguous stereogenic centers, the highly efficient Wittig reaction to install double bond and the indium-mediated gem-difluoropropargylation of aldehydes 67 and 68 with the fluorine-containing building block 10 to afford compounds 69,70, respectively, then the selective hydrogenation and deprotection of the primary tert-butyldimethylsilyl group to construct gem-difluoromethylenatedα,β-unsaturatedδ-lactones. The biological evaluation of these synthetic analogues was assayed.PartⅡ:Starting from available D-gluconoδ-lactone, we have synthesized two totally deacetylated gem-difluoromethylenated analogues of boronolide 99,100 and two gem-difluoromethylenated analogues of boronolide 101,102. Our synthesis features the efficient construction of the key intermediates 91 and 92 through the indium-mediated gem-difluoropropargylation of aldehyde 90 with the fluorine-containing building block 10. Beginning with the initial synthesized intermediate 87, we also have synthesized two gem-difluoromethylenated analogues of anamarine 133 and 134. The E configuration of the double bond segments in compounds 133 and 134 was constructed by means of the typical Horner-Wadsworth-Emmons reaction and the lactone was obtained by the oxidation of 1,5-diols spontaneously ring closure.更多还原