Diastereoselective addition of organomanganese compounds to chiral polyalkoxyaldehydes
作者:A. N. Kasatkin、I. P. Podlipchuk、R. K. Biktimirov、G. A. Tolstikov
DOI:10.1007/bf00704203
日期:1993.6
Organomanganesecompounds RMnI (R=Me, Pr, Bu, Hex, Ph, BuC≡C) prepared from RLi and MnI2 in Et2O react with 3-O-benzyl-1,2-O-isopropylidene-α-D-xylo-pentodialdo-1, 4-furanose, 1,2∶3,4-di-O-isopropylidene-α-D-galacto-hexodialdo-1,5-pyranose, andR-2,3-dibenzyloxypropanal to afford 4,5-threo-, 5,6-threo-, and 2,3-threo-isomeric products, respectively, with high diastereoselectivity.
Novel Synthesis of Disaccharides Containing the 2-Amino-2-deoxy-β-D-glucopyranosyl Unit and L-<i>Glycero</i>-D-<i>Manno</i>- and 7-Deoxy-L-<i>Glycero</i>-D-<i>Galacto</i>-heptopyranoses
Stereocontrolled syntheses of immunologically relevant heptopyranose disaccharides were achieved in excellent yields by the trimethylsilyl triflate promoted glycosylation of the donor 1,3,4,6-tetra-O-acetyl-2-N-allyloxycarbonyl-2-amino-2-deoxy-β-d-glucopyranose with the adequate acceptors.