Evidence of Robust Participation by equatorial 4-O group in glycosylation on a 2-Azido-2-deoxy-glucopyranosyl Donor
作者单位：复旦大学 Department of Medicinal Chemistry School of Pharmacy Fudan University School of Pharmaceutical Engineering Shenyang Pharmaceutical University
会议名称：《第二届糖合成化学青年学术研讨会》
会议日期：2017年
学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学]
摘 要：Neighboring group participation by 2-O-carboxylate esters is of fundamental importance to carbohydrate chemistry and thus the selective introduction of 1,2-trans bonds generally represents no ***,the potential participating effect of esters located on more remote positions of glycopyranosyl donors has not been unambiguously *** there are numerous claims of remote group participation leading to the synthesis of the expected glycosides with improved anomeric geometry outcome,there is still a lack of enough strong evidence and this has led to a long-term debate,particularly for equatorial 4-O group *** this work we synthesized and isolated a stable seven-membered trichlorooxazepine ring bridging intermediate by employing a 2-azido-2-deoxy-glucopyranosyl donor,which indicated the robust participation of the equatorial 4-O group in *** result offers new clues to better understand the participation character of protecting groups located on more remote positions of the glycosyl donors.