Mechanism of the reductive cleavage reaction of permethylated methyl d-glycopyranosides
作者:Chang Kiu Lee、Eun Ju Kim
DOI:10.1016/s0008-6215(99)00157-3
日期:1999.8
Abstract The mechanism of the reductive cleavage reaction of permethylated methyl d -glycopyranosides was investigated by measuring the rate of reaction. Glycosides employed were of α-Glc, β-Glc, α-Man, α-Gal, and β-Gal. Seven silanes were used to explore the reactivities of the reducing agents as well as to examine the stereoelectronic effects of the agents. Trimethylsilyl trifluoromethanesulfonate
摘要通过测量反应速率,研究了全甲基化甲基d-吡喃葡萄糖苷的还原裂解反应机理。使用的糖苷是α-Glc,β-Glc,α-Man,α-Gal和β-Gal。七种硅烷用于探索还原剂的反应性以及检查还原剂的立体电子效应。三氟甲磺酸三甲基甲硅烷基酯用作催化剂。通常,β-端基异构体的速率大约是α-端基异构体的速率的两倍。异构化速率比还原速率低约五到十倍。有人提议将环状氧鎓离子作为还原性裂解α-糖苷键的唯一中间体,