51295-60-4

Upstream product

• 108-24-7 acetic anhydride 
• 97-30-3 methyl-alpha-D-glucopyranoside 
• 3254-16-8 3,4,6-tri-O-acetyl-1,2-O-(1-methoxyethylidene)-β-D-mannopyranose 
• 27851-29-2 benzyl 2,3,4-tri-O-benzyl-D-glucopyranoside 
• 53008-65-4 methyl 2,3,4-tri-O-benzyl-D-glucopyranoside 
• 1197820-01-1 2-methoxy-2-(S)-phenyl-(3,4,6-tri-O-acetyl-1,2-dideoxy-β-D-glucopyranoso)[1,2-e]-1,4-oxathiane (R)-S-oxide 
• 67-56-1 methanol 
• 604-69-3 β-D-glucose pentaacetate 
• 604-70-6 Acetic acid (2R,3R,4S,5R,6S)-3,5-diacetoxy-2-acetoxymethyl-6-methoxy-tetrahydro-pyran-4-yl ester 

Relevant academic research and scientific papers

Methyl 1,2-orthoesters as useful glycosyl donors in glycosylation reactions: A comparison with n-pent-4-enyl 1,2-orthoesters

Mannopyranose-derived methyl 1,2-orthoacetates (R = Me) and -benzoates (R = Ph) can function as glycosyl donors - upon BF3·Et 2O activation in CH2Cl2 - in glycosylation reactions with monosaccharide acceptors to afford disaccharides in good yields. In the process, glycosylation is preferred to acid-catalyzed rearrangement leading to methyl mannopyranosides. Methyl 1,2-orthoesters can be also used in regioselective glycosylation protocols with monosaccharide diols, in which they display good regioselectivity. Copyright

Stereoselective glycosylation using oxathiane glycosyl donors

A bicyclic glycosyl donor is activated as an arylsulfonium ion and used to synthesise α-glycosides with high stereoselectivity.

Variations on the SnCl4 and CF3CO2Ag-promoted glycosidation of sugar acetates: a direct, versatile and apparently simple method with either α or β stereocontrol

Glycosidation of sugar peracetates (d-gluco, d-galacto) with SnCl4 and CF3CO2Ag led to either 1,2-cis-, or 1,2-trans-glycosides, depending primarily on the alcohols used. In particular, 1,2-trans-glycosides, expected from acyl-protected glycosyl donors, were formed in high yields with alcohols sharing specific features such as bulkiness, presence of electron-withdrawing groups or polyethoxy motifs. In contrast, simple alcohols afforded ～1:1 mixtures of 2,3,4,6-tetra-O-acetyl, and 3,4,6-tri-O-acetyl 1,2-cis-glycosides due to anomerization and/or acid-catalyzed fragmentation of 1,2-orthoester intermediates. After reacetylation or deacetylation, acetylated or fully deprotected 1,2-cis-glycosides (α-d-gluco, α-d-galacto) were obtained in ～90% yields by a simple and direct method.

Regioselective deacetylation of fully acetylated mono- and di-saccharides with hydrazine hydrate

Selective deacetylation reactions of the peracetylated reducing disaccharides (1), (5), (9), (15), β-D-glucopyranose (17) and 2-acetamido-2-deoxy-β-D-glucopyranose (19), with 1-2 equiv. of hydrazine hydrate in acetonitrile, gave predominantly the corresponding heptaacetates (2), (6), (10), (16), the tetraacetate (18) and the triacetate (20), with the free hydroxy group at C1. Reaction of (1) with 1-2 equiv. of hydrassine hydrate in N,N-dimethylformamide also afforded the heptaacetate (2), but in lower yield. When reactions of (1), (5) and (9) were performed with 2-5 equiv. of hydrazine hydrate, deacetylation also occurred at other positions to afford the corresponding hexaacetates (3), (7), (11) and (12), with hydroxy groups at C 1,2 or C 1,3, and the pentaacetates (4), (8) and (13), with hydroxy groups at C 1,2,3. Maltose octaacetate (9). in addition, yielded the tetraacetate (14) in which the free hydroxy groups were located at C1,2,2′,3. Compound (15) on treatment with 2-5 equiv. of hydrazine hydrate afforded an intractable mixture. The reaction of methyl 2,3,4,6-tetra-O-acetyl-α-D-glucopyranoside (21) with 2-5 equiv. of hydrazine hydrate gave the 3,4,6-triacetate (22), a mixture of the 2,6- and the 3,6-diacetates (23) and (24), respectively, the 4,6-diacetate (25), and the 6-acetate (26).

Novel methods for the preparation of partially acetylated carbohydrates

The selective acetylation of methyl α-D-hexopyranosides in the presence of zinc chloride shows unusual reactivity patterns compared to control experiments.Hydroperoxide ion is a mild and selective deacetylation reagent which does not attack primary acetates.