| 摘要: | 醣基化反應是醣化學中重要的一環，得到良好的產率及控制立體選擇性，一直是醣化學家致力研究的部分。傳統上，1,2-反式醣苷鍵的建構須仰賴鄰基效應而形成，而1,2-順式醣苷鍵則無法透過產生鄰近基效應獲得。
為了有效率地建構1,2-順式醣苷鍵，近幾年，許多研究團隊針對在不同醣類中，其C-3、C-4、C-6接上帶有酯基的保護基是否有遠程參與效應的產生進行探討，他們嘗試藉由光譜學、理論計算及實驗證明遠程參與效應的產生，然而其研究結果並無達成共識，導致其無法廣泛地參與到不同醣基化反應的策略中。
為了突破目前的困境，本文藉由實驗室先前建立之醣供體及醣受體反應性的預測模型，利用統計學的角度觀察醣基化反應的立體選擇性。實驗流程包括四個部分，製備N-疊氮化半乳糖胺(GalN3) 之醣供體及葡萄糖之醣受體、測量醣供體反應性 (RRV) 與醣供體反應性 (Aka) ，將其進行一系列醣基化反應，再透過本實驗室建立的RRV及Aka預測模型進行分析。
;Glycosylation reaction is an important part of glycoscience, and obtaining excellent yield and control of stereoselectivity has always been a field of focus for chemists. Traditionally, the construction of 1,2-trans glycosidic linkage relies on the neighboring group effect. However, an effective method for the synthesis of 1,2-cis glycosidic linkage is absent.
In recent years, reasearchers has explored whether there is a remote participation effect by installing ester-protecting groups to C-3, C-4, and C-6 in different glycosyl donors. They used various methods such as NMR (Nuclear Magnetic Resonance), IR (Infrared Spectroscopy), theoretical calculations, and the results of actual glycosylation reactions to demonstrate the occurrence of the remote participation effect. However, the experimental results have not reach a consensus, and the remote participation effect is still not effectively used in glycosylation reactions.
In our laboratory, a predictive model was established to analyze the stereoselectivity of glycosylation reaction by using the statistical approach. Therefore, we use the model to investigate the participating level of acetyl and benzoyl group at C-3、C-4、C-6 positions. The experimental process includes four parts: preparing GalN3 donors and Glu acceptors, detecting the reactivity of donors (RRV) and acceptors (Aka), doing a series of glycosylation reactions, and analyzing the correlation of stereoselectivity and remote participation effect. |
