over their O-linked counterparts. This paper reports the synthesis of several trans-2-(C-glycosyl)acetates via a tandem Wittig–Michael reaction from pyranoses (cyclic hemiacetals) using continuous flow processing, which gave improvements compared to reactions conducted in round-bottom flasks. Products were isolated in yields of >60% from reactions of benzyl-protected xylopyranoses, glucopyranoses, and
C-糖基化合物(C-糖苷)是一类糖衍
生物,其稳定性优于 O-连接对应物。本文报道了使用连续流动工艺,通过串联维蒂希-迈克尔反应从
吡喃糖(环状
半缩醛)合成了几种反式-2-(C-糖基)
乙酸酯,与在圆底烧瓶中进行的反应相比,该反应有所改进。在较高温度和压力下,从苄基保护的
吡喃
木糖、
吡喃
葡萄糖和
吡喃半
乳糖的反应中分离出的产物的产率>60%,这优于间歇程序的产率。开发了一种两步程序,涉及在
DBU 存在下获得的不饱和酯的 Wittig 反应和 Michael 反应(分子内 oxa-Michael)。由于竞争性 C-2 差向异构化,受保护的
吡喃
甘露糖的反应在流动中的相应反应中产生低产率。