Comparing n-pentenyl orthoesters and n-pentenyl glycosides as alternative glycosyl donors
作者:Mateusz Mach、Urs Schlueter、Felix Mathew、Bert Fraser-Reid、Kevin C Hazen
DOI:10.1016/s0040-4020(02)00671-3
日期:2002.9
As is well known, cyclic 1,2-glycosyl orthoesters undergo ready acid catalyzed rearrangement to 2-O-acyl glycosides in which the alkoxy group is transferred from the orthoester to the anomeric center in a highly stereocontrolled process. The related n-pentenyl derivatives are unique in that either the orthoester (NPOE) or its rearrangement product (NPGAC) can function as a glycosyl donor, and mechanistic
众所周知,环状1,2-糖基原酸酯经历了容易的酸催化重排成2- O-酰基糖苷,其中烷氧基以高度立体可控的过程从原酸酯转移到异头中心。相关的正戊烯基衍生物的独特之处在于原酸酯(NPOE)或它的重排产物(NPG AC)都可以作为糖基供体,并且从机械方面的考虑来看,两者都应该(或可能!)产生相同的产物。 )是由反式原酸酯化,糖苷化,糖基酯化等产生的。实验表明,通过精心选择供体,NPOE或相关的NPG AC,可以优化从给定反应获得的产物,并特别注意反应条件,亲电子启动子,糖基受体的“大小”和实验方案。