A series of novel guanidinoglycosides was successfully synthesized.  This was accomplished with the use of Mitsunobu conditions as a  strategy to convert the glycopyranose anomeric hydroxy group to  give the corresponding substituted masked guanidines in high yields.  Subsequent deprotection and coupling with Fmoc protected β-amino  acid, afforded a series of N,N′-substituted-methylisothioureas.  Cleavage of Fmoc followed by concomitant cyclization was achieved  with a catalytic amount of DBU to give the guanidinoglycosides.
                                    我们成功合成了一系列新型
胍类糖苷。  通过使用 Mitsunobu 条件作为一种策略,将糖
吡喃糖异构羟基转化为相应的取代掩蔽
胍类,产量很高。  随后进行脱保护并与 Fmoc 保护的δ-
氨基酸偶联,得到了一系列 N,N′-取代的甲基异
硫脲。  在一定量的 
DBU 催化下,Fmoc 发生裂解并同时发生环化反应,从而得到
鸟苷糖苷类化合物。