促進劑與醣受體於醣鏈結反應中的影響與薄膜層析法於固相反應之即時分析

Abstract

我們在本論文中討論了醣基氯與醣基三氟甲磺酸酯這兩種中間產物於醣鏈結反應中的角色，並提出了可能的反應機構。此反應機構可適用於對甲苯巰基氯/三氟甲磺酸銀與鹵化丁二醯亞胺/三氟甲磺酸的醣催化條件。此外，我們也發現醣受體的活性也會影響立體選擇性：活性越高越容易得到β位向的產物；反之，則越易獲得α位向產物。 我們也將二甲基甲醯胺作為添加物加入固相醣鏈結反應中，效果與其在液相反應中類似，均可獲得較多的α產物。此外，薄層層析法也應用至固相反應中，有利於化學家在固相反應中即時獲得反應的資訊，以便最佳化條件。 最後，我們從蛋黃萃取出寡醣，並應用本實驗室已開發的方法及討論過的反應機制，將此寡醣官能基化，及位置選擇性地安裝上岩藻醣，成為人體中具有的N-聚醣結構，以利於後續的研究。

We have discussed the roles of the intermediates, glycosyl halide and glycosyl triflate, during the glycosylation and proposed a plausible mechanism for p-TolSCl/AgOTf and NXS/TfOH conditions. Additionally, the reactivity of acceptor influences the stereoselectivity; namely, higher reactive acceptor prefers β-glycosylation and lower reactive acceptor favors α-product. The DMF-assisted stereoglycosylation was utilized in the solid-phase glycosylation successfully. Also, the real-time detection by thin-layer chromatography (TLC) for the solid-phase reaction was investigated and is believed to benefit this field. Finally, we functionalized and fucosylated a nonasaccharide based on the research in this thesis. The obtained nonasaccharide is going to further study.