129753-04-4

Upstream product

• 243136-79-0 4,6-O-benzylidene-1,2,3-tris-O-acetyl-D-galactopyranoside 
• 545-06-2 trichloroacetonitrile 

Downstream Products

• 173977-54-3 Benzyl O-(2,3-di-O-acetyl-4,6-O-benzylidene-β-D-galactopyranosyl)-(1->4)-2,3,6-tri-O-benzyl-α-D-glucopyranoside 
• 695177-44-7 Acetic acid (2S,4aR,6R,7R,8S,8aS)-8-acetoxy-6-((2R,3R,4R)-3-hydroxy-2-triisopropylsilanyloxymethyl-3,4-dihydro-2H-pyran-4-yloxy)-2-phenyl-hexahydro-pyrano[3,2-d][1,3]dioxin-7-yl ester 
• 1385090-43-6 p-chlorophenyl 2,3-di-O-acetyl-4,6-O-benzylidene-β-D-galactopyranosyl-(1->4)-3,6-di-O-benzyl-2-deoxy-2-phthalimido-1-thio-β-D-glucopyranoside 
• 1229735-01-6 C₄₅H₅₄O₁₃ 
• 173977-55-4 Benzyl O-(4,6-O-benzylidene-2,3-di-O-(p-methoxybenzyl)-β-D-galactopyranosyl)-(1->4)-2,3,6-tri-O-benzyl-α-D-glucopyranoside 
• 173977-57-6 Benzyl O-(6-O-benzyl-2,3-di-O-(p-methoxybenzyl)-β-D-galactopyranosyl)-(1->4)-2,3,6-tri-O-benzyl-α-D-glucopyranoside 

Relevant academic research and scientific papers

Synthesis of a sialyl-α-(2→6)-lactosamine trisaccharide with a 5-amino-3-oxapentyl spacer group at C-1

As part of a continuing study aimed to achieve improved monoclonal antibodies against carcinoembryonic antigen (CEA) carbohydrate fragments, the synthesis of a sialyl-(2→6)-lactosamine trisaccharide with a 5-amino-3-oxapentyl spacer group at C-1(I) has been developed. Two different routes to access this target are described. For this purpose 5-azido-3-oxapentyl 6-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranoside (4) was selectively β-galactosylated in 81% yield using the crystalline 2,3-di-O-acetyl-4,6-O-benzylidene-α-D-galactopyranosyl trichloroacetimidate as the donor, taking advantage of the bulky phthalimido group at C-2 of 4. On the other hand, galactosylation of the suitable protected acceptor 5-azido-3-oxapentyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-β-D-glucopyranoside with the crystalline 2,3-di-O-acetyl-4,6-O-benzylidene-α-D-galactosyl bromide renders the corresponding disaccharide in a moderate 58% yield. Despite the fact that the first strategy, unlike the second one, requires a hydrazinolysis-acetylation reaction at the disaccharide stage, it was found to be more convenient to access the disaccharide acceptor. Sialylation was performed using a thiophenyl donor under an NIS-TfOH activation procedure in acetonitrile to give a mixture of α and β trisaccharides in 49 and 16% yields, respectively. Copyright (C) 1999 Elsevier Science Ltd.

Glycosyl Imidates, 62. Synthesis of the Heptasaccharide Moiety of Ganglioside BGM1

The synthesis of the O-acetyl protected heptasaccharide moiety (2) of BGM1 was performed according to the following reaction sequence: Reaction of 2,3-di-O-acetyl-4,6-O-benzylidenegalactosyl trichloroacetimidate 4 (as donor) with 3-O-unprotected 2-azidogalactose 5 (as acceptor) gave β(1->3)-connected disaccharide 6.Subsequent O-deacetylation followed by reaction with galactosyl donor 8 afforded regioselectively trisaccharide 9 which was converted into tetrasaccharide 12 by treatment with fucosyl donor 11.Transformation of 12 via acid-catalyzed O-deisopropylidenation, O-acetylation, anomeric O-desilylation, and then base-catalyzed treatment with trichloroacetonitrile afforded trichloroacetimidate 16 as tetraosyl donor.Reaction of 16 with the known 4b-O-unprotected sialyllactose derivative 17 gave in acetonitrile at -40 deg C in the presence of TMSOTf as the catalyst the desired heptasaccharide 18.Azido group reduction with propanedithiol, N-acetylation, hydrogenolytic O-debenzylation, and O-debenzylidenation under acidic conditions followed by O-acetylation afforded the target molecule 2.The structural assignments were based on the 1H-NMR data. Key Words: Glycosphingolipids / Ganglio series / Blood group B determinant / Glycosides /Trichloroacetimidates / Saccharides / Carbohydrates