Phenyl 2-Deoxy-2-iodo-1-thio-glycosides: New Glycosyl Donors for the Stereoselective Synthesis of 2-Deoxy-oligosaccharides
作者:Yolanda Díaz、Sergio Castillón、Xavier Arnés
DOI:10.1055/s-2003-42066
日期:——
Phenyl 2-deoxy-2-iodo-1-thioglycosides, prepared from simple pentoses by olefination and iodine-induced cyclization, have proved to be efficient glycosyl donors for the stereoselective synthesis of 2-deoxy-2-iodo-oligosaccharides, which are precursors of 2-deoxy-oligosaccharides.
Tuning the Stereoelectronic Properties of 1-Sulfanylhex-1-enitols for the Sequential Stereoselective Synthesis of 2-Deoxy-2-iodo-β-<scp>d</scp>-allopyranosides
the best performer for the synthesis of cholesteryl 2-deoxy-2-iodomannopyranosides, whereas for the synthesis of 2-deoxy-2-iodoallopyranosides none of the derivatives here studied proved superior to the phenyl analogue previously described. Glycosylation of cholesterol with different d-allo and d-manno derivatives produced 2-deoxy-2-iodoglycosides with stereoselectivities in the same order in each case
挑战2-脱氧-2-碘-β-的制备d -同种异体2-脱氧β-的前体d -核糖-hexopyranosyl单元和其它类似物被使用鲁棒烯环化糖基化序列的报道。在这里,我们特别关注于调整烯基硫化物中间体的立体电子性质,以提高环化步骤的非对映选择性,从而提高整体转化的效率。易于合成通式为Ph 2 P(O)CH 2 SR(R = t -Bu,Cy,p -MeOPh,2,6-di-ClPh和2,6-di-MePh)的氧化膦用于与2,3,5-tri-Ø苄基d核糖和- d -arabinose。相应的糖衍生的烯基硫醚经过6-内[I + ]诱导的环化反应,所得的2-deoxy-2-iodohexopyranosyl-1-thioglycosides被用作糖基供体,用于2-脱氧-的立体选择性合成。 2-碘己基吡喃糖基糖苷。在研究的不同S-基团中,t- Bu衍生物是合成胆固醇基2-脱氧-2-碘代甘露吡喃喃糖苷的最
Stereoselective Synthesis of 2-Deoxy-2-iodo-glycosides from Furanoses. A New Route to 2-Deoxy-glycosides and 2-Deoxy-oligosaccharides of <i>r</i><i>ibo </i>and <i>x</i><i>ylo</i> Configuration
procedure involves three reactions: Wittig−Horner olefination to give alkenyl sulfanyl derivatives, electrophilic iodine-induced cyclization to give phenyl 2-deoxy-2-iodo-1-thio-hexo-glycosides, and glycosylation. Protected furanoses 1, 3, and 6−11, which include examples of the four possible isomeric configurations of furanoses, were reacted with diphenyl phenylsulfanylmethyl phosphine oxide to give the