作者:Ming Zhao、Yuji Wang、Caixia Huo、Chunyu Li、Xiaoyi Zhang、Li Peng、Shiqi Peng
DOI:10.1016/j.tetasy.2009.01.014
日期:2009.2
were converted to α- and β-anomers of N-(2,3,5-tri-O-acetyl-l-arabinofuranosyl)-N-(2-nitrobenzenesulfonyl)-l-amino acids, 3a–f-α and 3a–f-β, in 87–92% yields. While in the presence of NaOCH3, 3a–f-α and 3a–f-β were converted to α- and β-anomers of N-(l-arabinofuranosyl)-N-(2-nitrobenzenesulfonyl)-l-amino acids, 4a–f-α and 4a–f-β, in 90–96% yields. Treating 4a–f-α and 4a–f-β with N-ethyldiisopropylamine
在铅解毒中,N-糖基-1-氨基酸的α-端基异构体比其β-端基异构体更有效。这里报道了用于立体选择性地制备N-(α-1-阿拉伯糖-1-基)-1-氨基酸的六步反应路线。用乙酸酐和乙酸钠处理1-阿拉伯糖,得到90%产率的1,2,3,5-四-O-乙酰基-1-阿拉伯呋喃糖。除去1-乙酰基后,将由此形成的2,3,5-三-O-乙酰基-1-阿拉伯呋喃糖和N-(2-硝基苯基磺酰基)-1-氨基酸叔丁基酯用三苯基膦处理以进行Mitsunobu脱水并形成2,3,5-三-O-乙酰基-1-阿拉伯呋喃糖基-1- [ N-(2-硝基苯基磺酰基)]氨基酸叔丁基酯2a-f,其α-与β-端基异构体的比例为8/1至9/1。色谱分离提供差向异构纯2a–f-α和2a–f-β。在存在CF 3 CO 2 H的情况下,2a–f-α和2a–f-β转化为N-(2,3,5-三-O-乙酰基-1-阿拉伯呋喃糖基)的α-和β-异头物。- ñ - (2