384346-84-3

Upstream product

• 136523-92-7 N-(9-fluorenylmethoxycarbonyl)-L-threonine allyl ester 
• 618115-52-9 4-pentenyl 2-azido-4,6-O-benzylidene-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-β-D-galactopyranoside 
• 618115-57-4 2-azido-4,6-O-benzylidene-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-α-D-galactopyranosyl 2,2,2-trichloroacetimidate 
• 273944-57-3 N^α-fluoren-9-ylmethoxycarbonyl-3-O-(2-azido-4,6-O-benzylidene-2-deoxy-α-D-galactopyranosyl)-L-threonine allyl ester 
• 3068-32-4 1-bromo-1-deoxy-2,3,4,6-tetra-O-acetyl-a-D-galactopyranoside 
• 68733-05-1 peracetylated α-glycosyl nitrate 2-azido-2-deoxy-D-galactopyranose 
• 196398-25-1 3,4,6-tri-O-acetyl-2-azido-2-deoxy-α/β-D-galactopyranosyl nitrate 
• 4098-06-0 triacetyl-D-galactal 
• 618115-44-9 4-pentenyl 2-azido-2-deoxy-β-D-galactopyranoside 
• 618115-48-3 4-pentenyl 2-azido-4,6-O-benzylidene-2-deoxy-β-D-galactopyranoside 
• 3947-62-4 2,3,4,6-tetra-O-acetyl-α/β-D-galactopyranose 
• 384346-81-0 N^α-fluoren-9-ylmethoxycarbonyl-3-O-(2-azido-4,6-O-benzylidene-3-O-tert-butyldimethylsilyl-2-deoxy-α-D-galactopyranosyl)-L-threonine allyl ester 
• 384346-80-9 4-methylphenyl 2-azido-4,6-O-benzylidene-3-O-tert-butyldimethylsilyl-2-deoxy-1-thio-β-D-galactopyranoside 
• 125760-23-8 4-methylphenyl 2-azido-4,6-O-benzylidene-2-deoxy-1-thio-β-D-galactopyranoside 

Downstream Products

• 384346-85-4 N^α-fluoren-9-ylmethoxycarbonyl-3-O-[2-acetamido-4,6-O-benzylidene-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-α-D-galactopyranosyl]-L-threonine allyl ester 
• 174783-86-9 N^α-fluoren-9-ylmethoxycarbonyl-3-O-[2-acetamido-4,6-O-benzylidene-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-α-D-galactopyranosyl]-L-threonine 

Relevant academic research and scientific papers

Highly efficient preparation of tumor antigen-containing glycopeptide building blocks from novel pentenyl glycosides

O-Glycosylated amino acids containing the tumor-associated T(T f)-antigen (β-D-Gal-(1→3)-α-D-GalNAc) disaccharide unit were conveniently synthesized in seven steps starting from D-galactose via an n-pentenyl glycoside (NPG) building block. Azidonitration of 3,4,6-tri-O-acetyl-D-galactal, followed by nitrate displacement with simultaneous acetate hydrolysis with sodium 4-penten-1-oxide, afforded n-pentenyl 2-deoxy-2-azidogalactoside (3) in near quantitative yield. Subsequent high-yielding transformations resulted in the synthesis of the key glycosyl donor n-pentenyl β-disaccharide 5 that was employed for the stereospecific preparation of glycosyl amino acids via NIS-promoted glycosylations with serine or threonine acceptors. The surprising utility of the reaction of sodium 4-penten-1-oxide with anomeric nitrates encouraged the detailed exploration of the action of a variety of nucleophiles on anomeric nitrates for the synthesis of useful 2-azido glycosyl donors directly from the 'classic' Lemieux azidonitration product of protected galactals. This expedient synthesis (28% overall yield from 1 to 7a) that makes use of heretofore rarely exploited pentenyl 2′-azidoglycosides, should be a valuable entry in the armamentarium of routes to biologically relevant glycopeptides in both mono- and multivalent forms.

Chemoenzymatic synthesis of sialylated glycopeptides derived from mucins and T-cell stimulating peptides

The Tn, T, sialyl-Tn, and 2,3-sialyl-T antigens are tumor-associated carbohydrate antigens expressed on mucins in epithelial cancers, such as those affecting the breast, ovary, stomach, and colon. Glycopeptides carrying these antigens are of interestfor development of cancer vaccines and a short, chemoenzymatic strategy for their synthesis is reported. Building blocks corresponding to the Tn (Ga1NAcα-Ser/Thr) and T [Galβ(1→3)Ga1NAcα-Ser/Thr] antigens, which are relatively easy to obtain by chemical synthesis, were prepared and then used in the synthesis of glycopeptides on the solid phase. Introduction of sialic acid to give the sialyl-Tn [Neu5Acα(2→6)Ga1NAcα-Ser/Thr] and 2,3-sialyl-T [Neu5Acα(2→3)Ga1β(1→3)Ga1NAcα-Ser/ Thr] antigens is difficult when performed chemically at the building block level. Sialylation was therefore carried out with recombinant sialyltransferases in solution after cleavage of the Tn and T glycopeptides from the solid phase. In the same manner, the core 2 trisaccharide [Ga1β1→3(G1cNAcβ1→6)Ga1NAc] was incorporated in glycopeptides containing the T antigen by using a recombinant N-acetylglucosaminyltransferase. The outlined chemoenzymatic approach was applied to glycopeptides from the tandem repeat domain of the mucin MUCl, as well as to neoglycosylated derivatives of a T cell stimulating viral peptide.