246875-56-9

Upstream product

• 77481-63-1 phenyl-1-thio-β-D-mannopyranoside 
• 58479-61-1 tert-butylchlorodiphenylsilane 

Downstream Products

• 246875-57-0 phenyl 6-O-tert-butyldiphenylsilyl-2,3-O-isopropylidene-1-thio-β-D-mannopyranoside 
• 1447946-73-7 phenyl 3-O-benzoyl-6-O-t-butyldiphenylsilyl-1-thio-β-D-mannopyranoside 
• 1447946-72-6 phenyl 3-O-acetyl-6-O-t-butyldiphenylsilyl-1-thio-β-D-mannopyranoside 
• 1447946-78-2 phenyl 4-O-acetyl-2-azido-2-deoxy-6-O-t-butyldiphenylsilyl-1-thio-β-D-galactopyranoside 
• 1447946-77-1 phenyl 4-azido-3-O-benzoyl-4-deoxy-6-O-t-butyldiphenylsilyl-1-thio-β-D-galactopyranoside 
• 1447946-76-0 phenyl 3-O-acetyl-4-azido-4-deoxy-6-O-t-butyldiphenylsilyl-1-thio-β-D-galactopyranoside 
• 1301693-40-2 phenyl 2-azido-2-deoxy-3-O-benzoyl-6-O-tert-butyldiphenylsilyl-1-thio-β-D-galactopyranoside 
• 1301693-39-9 phenyl 3-O-acetyl-2-azido-2-deoxy-6-O-tert-butyldiphenylsilyl-1-thio-β-D-galactopyranoside 
• 1447946-75-9 phenyl 2,4-diazido-3-O-benzoyl-2,4-dideoxy-6-O-t-butyldiphenylsilyl-1-thio-β-D-galactopyranoside 
• 1447946-74-8 phenyl 3-O-acetyl-2,4-diazido-2,4-dideoxy-6-O-t-butyldiphenylsilyl-1-thio-β-D-galactopyranoside 
• 1447946-84-0 N-(benzyloxycarbonyl)-O-(4-O-acetyl-2-azido-3-O-chloroacetyl-2-deoxy-α-D-galactopyranosyl)-L-serine methyl ester 
• 1447946-83-9 N-(benzyloxycarbonyl)-O-(4-O-acetyl-2-azido-2-deoxy-6-O-t-butyldiphenylsilyl-α-D-galactopyranosyl)-L-serine methyl ester 
• 1447946-82-8 N-(benzyloxycarbonyl)-O-(4-O-acetyl-2-azido-3-O-chloroacetyl-2-deoxy-6-O-t-butyldiphenylsilyl-α-D-galactopyranosyl)-L-serine methyl ester 
• 1447946-81-7 phenyl 2-azido-3-O-benzoyl-2,4,6-trideoxy-4-phthalimido-α-D-galactopyranosyl(1→4)-3-O-acetyl-2-azido-2-deoxy-6-O-t-butyldiphenylsilyl-1-thio-β-D-galactopyranoside 

Relevant academic research and scientific papers

Orthogonally protected d-galactosamine thioglycoside building blocks via highly regioselective, double serial and double parallel inversions of β-d-thiomannoside

An efficient route for the synthesis of orthogonally protected d-galactosamine thioglycosides via one-pot double serial and double parallel displacements of the d-mannosyl-2,4-bis-trifluoromethanesulfonates by azide and nitrite ions is described. These bu

Total Synthesis of the Repeating Unit of Bacteroides fragilis Zwitterionic Polysaccharide A1

Zwitterionic polysaccharides isolated from commensal bacteria are endowed with unique immunological properties and are emerging as immunotherapeutic agents as well as vaccine carriers. Reported herein is a total synthesis of the repeating unit of Bacteroides fragilis zwitterionic polysaccharide A1 (PS A1). The structurally complex tetrasaccharide unit contains a rare sugar 2-acetamido-4-amino-2,4,6-trideoxy-d-galactose (AAT) and two consecutive 1,2-cis glycosidic linkages. The repeating unit was efficiently assembled by rapid synthesis of d-galactosamine and AAT building blocks from cheap and abundant d-mannose via a one-pot SN2 displacement of 2,4-bistriflates and installation of all of the glycosidic bonds in a highly stereoselective manner. The total synthesis involves a longest linear sequence of 17 steps with 3.47% overall yield.

Stereoselectivity of glycosylations of conformationally restricted mannuronate esters

Glycosidation of conformationally unrestricted mannuronate ester donors proceeds in a highly β-selective fashion, whereas condensations of mannuronate ester donors, which are conformationally constrained by a 3,4-butanedimethylacetal or a 2,3-isopropylidene function, provide α-selective products. We hypothesize that the difference in stereochemical outcome of these condensations results from the different conformations of the product forming oxacarbenium intermediate. The formation of the β-linked products from the flexible mannuronates is thought to originate from the most favorable 3H4 oxacarbenium ion, which is not accessible from the conformationally restrained donors. Although an α-triflate intermediate is formed upon activation of the 3,4-butanedimethylacetal protected mannuronate ester thio donor, this is not the product forming intermediate. The anomeric triflate serves as a reservoir for the 4H3 oxacarbenium ion, which is glycosidated to provide the α-linked mannuronates.