Glycosidation of 2,5-anhydro-3,4-di-O-benzyl-D-mannitol with different glucopyranosyl donors: a comparative study.
2,5-Anhydro-3,4-di-O-benzyl-D-mannitol was glycosylated using different donors such as tetra-O-acetyl-alpha-D-glucopyranosyl bromide in the presence of Hg(CN)(2), the corresponding beta-thiophenylglycoside in the presence of NIS and TfOH as well as the alpha- and beta-trichloroimidate with TMSOTf as promoter. The resulting mixtures were analyzed by HPLC and the following main components were isolated and characterized: 2,5-anhydro-3,4-di-O-benzyl-1-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-d-mannitol; 6-O-acetyl-2,5-anhydro-3,4-di-O-benzyl-1-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-D-mannitol; 2,5-anhydro-3,4-di-O-benzyl-1,6-bis-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-D-mannitol; 2,5-anhydro-3,4-di-O-benzyl-1-O-[-2-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-3,4,6-tri-O-acetyl-beta-D-glucopyranosyl]-6-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-D-mannitol and 2,5-anhydro-3,4-di-O-benzyl-1,6-bis-O-(3,4,6-tri-O-acetyl-1,2-O-ethylidene-2'-yl-alpha-D-glucopyranosyl)-D-mannitol. The latter compound representing a bis-orthoester might be a common intermediate in all the investigated reactions, as its rearrangement and/or decomposition can yield all of the isolated compounds.
IVAX Drug Research Institute, PO Box 82, 1325 Budapest, Hungary.
Anikó
A
Tegdes
Gábor
G
Medgyes
Sándor
S
Boros
János
J
Kuszmann
D006027:Glycosides / Q000737:chemistry* / Q000378:metabolism*; D006031:Glycosylation; D009682:Magnetic Resonance Spectroscopy; D008353:Mannitol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure
C512146:2,5-anhydro-3,4-di-O-benzylmannitol; D006027:Glycosides; D008353:Mannitol