Hydrogen atom transfer experiments provide chemical evidence for the conformational differences between C- and O-glycosides
作者:Angeles Martín、Luis M. Quintanal、Ernesto Suárez
DOI:10.1016/j.tetlet.2007.05.166
日期:2007.7
reaction promoted by alkoxyl radicals generated from 3-hydroxypropyl α-d-mannopyranoside derivative (O-glycoside) and 2,6-anhydro-d-glycero-d-manno-decitol derivative (C-glycoside) is studied. The O-glycoside model abstracts preferentially the hydrogen atom at C-5 (1,8-HAT) while the C-glycoside abstracts the hydrogen atom at C-1 (1,6-HAT) but no abstraction at C-5 could be detected. These results are explained
3-羟丙基α-d-甘露吡喃糖苷衍生物(O-糖苷)和2,6-脱水-d-甘油-d-甘露糖醇衍生物(C -糖苷)。该Ô糖苷模型抽象优先在C-5(1,8-HAT)上的氢原子而Ç糖苷抽象在C-1(1,6-HAT)上的氢原子,但在C-5可以是没有抽象检测到。这些结果通过在O-糖苷中的外-异头作用所施加的立体电子控制来解释。