1. 以二甲基甲醯胺調控醣基化反應合成2,6-雙去氧-a-醣苷鍵，並延伸至一鍋化、迭代醣基化反應。2. 利用保護基Picolinoyl -對醣受體產生遠端引導效應合成去氧-b-醣苷鍵

Abstract

去氧醣在許多的抗生素以及藥物分子中都扮演著重要的腳色。然而，因為去氧醣的特性使它在化學合成與控制上有許多困難，如何有效率的合成去氧醣以及含去氧醣的寡醣是醣化學領域中很熱門的課題。 在過去，我們實驗室發現在醣基化反應中添加些許的DMF能夠大大的提升a選擇性。另一方面，DMF調控醣基化反應具有預活化的步驟，很有潛力發展為連續醣基化反應。在這個研究中，我們將DMF醣基化反應應用到不同的去氧醣，包括2-去氧半乳醣以及2,6-雙去氧半乳醣。此外，我們更進一步地將此方法結合一鍋化連續醣基化策略進行包含去氧醣之寡糖鏈的合成。 保護基團也是影響著醣基化反應的重要因子。Demchenko和他的團隊發現遠端的O-Picolinoyl能夠對醣基化反應有一定程度的影響。他們推測O-Picolinoyl能藉由氫鍵引導醣受體至同側，使醣受體從特定位向生成醣苷鍵。我們將這樣的概念應用至去氧-b-醣苷鍵的合成，發展為新的去氧-b-醣苷鍵合成方法。

Deoxysugars play an important role in many antibiotic and pharmaceutical molecules. Therefore, chemical synthesis of 2-deoxy- and 2,6-dideoxyglycoside-containing oligosaccharides are always an interesting topic in carbohydrate field. Our group have found that several additional DMF in glycosylation reaction can significantly increase a selectivity. Recently, we applied this method to different deoxysugars , including 2-deoxygalactose and 2,6-dideoxygalactose. Furthermore, we successfully applied one-pot, iterative, DMF modulated glycosylation to the synthesis of a deoxyglycoside-containing trisaccharides. Protecting groups are also an important factor in glycosylation. Demchenko and co-workers have found that remote O- Picolinoyl group can mediate glycosylation. Picolinoyl may form hydrogen-bond with acceptor and deliver it to the active site from syn side. We applied this concept to the synthesis of 2-deoxy-b-glycosides.