Details

Autor(en) / Beteiligte

• Tyrtysh, Tatiana V.
• Korchagina, Elena Yu
• Ryzhov, Ivan M.
• Bovin, Nicolai V.

Titel

Gram scale synthesis of A (type 2) and B (type 2) blood group tetrasaccharides through 1,6-anhydro-N-acetyl-β-D-glucosamine

Ist Teil von

• Carbohydrate research, 2017-09, Vol.449, p.65-84

Ort / Verlag

Netherlands: Elsevier Ltd

Erscheinungsjahr

2017

Quelle

MEDLINE

Beschreibungen/Notizen

• Gram scale synthesis of A (type 2) and B (type 2) tetrasaccharides in the form of 3-aminopropyl glycosides is proposed starting from 3-O-benzoyl-1,6-anhydro-N-acetylglucosamine. Its galactosylation followed by re-protection gave lactosamine derivative with single free 2′-OH group in total yield 75%. Standard fucosylation and next run of re-protection in total yield 88% gave a trisaccharide Fuc-Gal-anhydroGlcNAc with single free 3′-OH group. Its standard α-galactosylation gave protected B (type 2) tetrasaccharide. For synthesis of correspondent A tetrasaccharide seven different 2-azido-2-deoxygalactosyl (GalN3) donors were tested: 6-O-acetyl-3,4-O-isopropylidene-GalN3 thioglycoside was shown to provide the best yield (89%) and stereoselectivity (α/β = 24:1). Further 1,6-anhydro cycle opening, spacer-arming and complete deprotection resulted in the target 3-aminopropyl glycosides of A (type 2) and B (type 2) tetrasaccharides, yields 87 and 85% correspondingly. [Display omitted] •Gram scale synthesis of spacer-armed A and B (type 2) tetrasaccharides.•1,6-Anhydro-GlcNAc is convenient synthon for synthesis of glycans with LacNAc core.•6-OAc-3,4-O-isopropylidene-GalN3SEt is a superior reagent for α-galactosaminylation.