The synthesis of the first multivalent pyrrolizidine iminosugars is reported. The key azido intermediates 4 and 31 were prepared after suitable synthetic elaboration of the cycloadduct obtained from 1,3-dipolar cycloaddition of D-arabinose derived nitrone to dimethylacrylamide. The key step of the strategy was the stereoselective installation of an azido moiety at C-6 of the pyrrolizidine skeleton. The click reaction with different monovalent and dendrimeric alkyne scaffolds allowed the preparation of a library of new mono- and multivalent pyrrolizidine compounds that were preliminarily assayed as glycosidase inhibitors towards a panel of commercially available glycosyl hydrolases.
首次报道了多价
吡咯并
吡嗪亚胺糖的合成。通过对从
D-阿拉伯糖衍生的亚硝基与二甲基
丙烯酰胺进行1,3-偶极环加成反应得到的环加成产物进行适当的合成改良,制备了关键的
叠氮中间体4和31。该策略的关键步骤是在
吡咯并
吡嗪骨架的C-6位进行立体选择性的
叠氮基团的引入。通过与不同的一价和树枝状炔基骨架进行点击反应,制备了一系列新的单价和多价
吡咯并
吡嗪化合物,这些化合物被初步检测为对商业可得的糖基
水解酶的糖苷酶
抑制剂。