with C5-amino gave 4C-dihydroxymethyl pyrrolidine iminosugars 1b and 1c, respectively. On the basis of the 1H NMR studies, the conformations of 2a/2b were assigned as 4C1 and that of 2c as 1C4. The glycosidase inhibitory activities of all five iminosugars were studied with various glycosidase enzymes and compared with natural d-gluco-1-deoxynojirimycin (DNJ). All the five compounds were found to be potent
二
氯甲基锂与适当保护的5-酮-六
呋喃糖酶的Jocic-Reeve和Corey-Link型反应,然后用
叠氮化
钠和
硼氢化钠处理,得到具有所需双键二羟甲基基团的5-
叠氮基-
5-羟甲基取代的六
呋喃糖酶7a - c。去除保护基并将C-1异头碳转化为游离
半缩醛,然后分子内还原性
氨基环化并原位生成C5-
氨基官能团,得到相应的5C-二羟甲基
哌啶亚
氨基糖2a – c。或者,去除7b和7c中的保护基将C 1-异头碳切断,得到C 2-醛,然后用C 5-
氨基进行分子内还原性
氨基环化,分别得到4 C-二羟甲基
吡咯烷亚
氨基糖1b和1c。根据1 H NMR研究,将2a / 2b的构象指定为4 C 1,将2c的构象指定为1 C 4。所有五个亚
氨基
糖类的糖苷酶抑制活性进行了研究各种糖苷酶和天然相比d -
葡萄糖-1-脱氧野oji霉素(DNJ)。发现所有这五种化合物都是
水稻α-
葡萄糖苷酶的有效
抑制剂,其K i和IC 50值在纳