On the Use of 3,5-<i>O</i>-Benzylidene and 3,5-<i>O</i>-(Di-<i>tert</i>-butylsilylene)-2-<i>O</i>-benzylarabinothiofuranosides and Their Sulfoxides as Glycosyl Donors for the Synthesis of β-Arabinofuranosides: Importance of the Activation Method
作者:David Crich、Christian Marcus Pedersen、Albert A. Bowers、Donald J. Wink
DOI:10.1021/jo061440x
日期:2007.3.1
1-benzenesulfinyl piperidine, or diphenyl sulfoxide, and trifluoromethanesulfonic anhydride in dichloromethane at −55 °C, reaction with glycosyl acceptors affords anomeric mixtures with little or no selectivity. The analogous 2-O-benzyl-3,5-O-(di-tert-butylsilylene)-α-d-thioarabinofuranoside also showed no significant selectivity under the 1-benzenesulfinyl piperidine or diphenyl sulfoxide conditions. With N-iodosuccinimide
A 2- ø -苄基-3,5- ø -亚苄基- α- d -thioarabinofuranoside通过在碱性条件下α,α-二溴甲苯相应二醇的反应来获得。在-55°C下用1-苯亚磺酰基哌啶或二苯亚砜和三氟甲磺酸酐在二氯甲烷中活化后,与糖基受体的反应可提供极少或没有选择性的异头混合物。在1-苯亚磺酰基哌啶或二苯基亚砜条件下,类似的2 - O-苄基-3,5 - O-(二叔丁基亚甲硅烷基)-α- d-硫代阿拉伯呋喃糖苷也没有显示出明显的选择性。与N-碘代琥珀酰亚胺和三氟甲磺酸银表明,甲硅烷基乙缩醛具有中等至高的β-选择性,而与起始硫代糖苷的构型无关。用三氟甲磺酸酐活化后的2 - O-苄基-3,5 - O-(二叔丁基亚甲硅烷基)-α-阿拉伯呋喃糖基亚砜供体也获得了高β-选择性。N获得的高β选择性-碘代琥珀酰亚胺/三氟甲磺酸银和亚砜的方法与常见的中间体一致,最有可能是氧杂碳鎓离子。用1-苯亚磺酰基