Synthesis of 2-Deoxy-2-<i>C</i>-alkyl Glycal and Glycopyranosides from 2-Hydroxy Glycal Ester
作者:Gour Chand Daskhan、Narayanaswamy Jayaraman
DOI:10.1021/jo202240f
日期:2012.3.2
glycal ester to the corresponding 2-deoxy-2-C-alkyl glycal in a facile manner, through key reactions including (i) C-allylation at C-1, (ii) Wittig reaction, and (iii) Cope rearrangement of a 1,5-diene derivative, is reported. The α-anomer of the 1,5-diene derivative underwent Cope rearrangement to afford 2-deoxy-2-C-glycal derivative, whereas the β-anomer was found to be unreactive. Employing this sequence
的方法,2-羟基烯糖酯转化成相应的2-脱氧-2- Ç烷基烯糖以容易的方式,通过关键反应包括:(i)C ^ -allylation在Ç -1,(ⅱ)Wittig反应,和( iii)报道了应对1,5-二烯衍生物的重排。对1,5-二烯衍生物的α-端基异构体进行Cope重排,得到2-脱氧-2- C-糖基衍生物,而发现β-端基异构体没有反应性。使用该序列中,3,4,6-三- ø -苄基-2- ø -乙酰基-1,5-脱水- d -阿拉伯糖-己-1- enitol转化到3,4,6-三ö -苄基-2-脱氧-2- C-烷基-1,5-脱水-d -阿拉伯糖-己-1- enitol。2-脱氧-2- C-烷基糖基衍生物是制备2-脱氧-2- C-烷基糖苷的合适的糖基供体,其通过卤代糖基化和随后的脱卤作用而介导。因此由该糖基制备了许多2-还原氧基-2- C-烷基糖苷,在还原端具有糖基和非糖基部分。