title: Block synthesis of A (type 2) and B (type 2) tetrasaccharides related to the human ABO blood group system.
abstract: Herein we report the synthesis of 3-aminopropyl glycosides of A (type 2) and B (type 2) tetrasaccharides via [3 + 1] block scheme. Peracetylated trichloroacetimidates of A and B trisaccharides were used as glycosyl donors. The well-known low reactivity of 4-OH group of N-acetyl-d-glucosamine forced us to test four glucosamine derivatives (3-Bz-1,6-anhydro-GlcNAc and 3-trifluoroacetamidopropyl β-glycosides of 3-Ac-6-Bn-GlcNAc, 3-Ac-6-Bn-GlcN3, and 3-Ac-6-Bn-GlcNAc2) to select the best glycosyl acceptor for the synthesis of type 2 tetrasaccharides. The desired tetrasacchrides were not isolated, when 3-trifluoroacetamidopropyl glycosyde of 3-Ac-6-Bn-GlcNAcβ was glycosylated. Glycosylation of 3-Bz-1,6-anhydro-GlcNAc derivative resulted in α-glycoside as a major product. High stereospecificity was achieved only in the synthesis of B (type 2) tetrasaccharide, when 3-trifluoroacetamidopropyl 3-Ac-6-Bn-GlcNAc2β was applied as the glycosyl acceptor (β/α 5:1), whereas glycosylation with trichloroacetimidate of A trisaccharide was not stereospecific (β/α 1.3:1). Glycosylation of 3-trifluoroacetamidopropyl glycoside of 3-Ac-6-Bn-GlcN3β with trichloroacetimidates of A and B trisaccharides provided the same stereochemical yield (β/α 1.5:1).
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation.
authors.forename: Ivan M
authors.initials: IM
authors.lastname: Ryzhov
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation. Electronic address: ellyu@yandex.ru.
authors.forename: Elena Yu
authors.initials: EY
authors.lastname: Korchagina
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation.
authors.forename: Inna S
authors.initials: IS
authors.lastname: Popova
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation.
authors.forename: Tatiana V
authors.initials: TV
authors.lastname: Tyrtysh
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Paramonov
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation. Electronic address: professorbovin@yandex.ru.
authors.forename: Nicolai V
authors.initials: NV
authors.lastname: Bovin
mesh_terms: D000017:ABO Blood-Group System / Q000737:chemistry*; D002240:Carbohydrate Sequence; D060326:Chemistry Techniques, Synthetic; D006031:Glycosylation; D006801:Humans; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D011714:Pyrans / Q000737:chemistry
chemical_list: D000017:ABO Blood-Group System; D009844:Oligosaccharides; D011714:Pyrans
keywords: 2-Azido-2-deoxy-glucose; ABO histo-blood group antigens; Block-synthesis; N,N-Diacetylglucosamine; N-Acetyl-1,6-anhydro-glucosamine; Trichloroacetimidate glycosylation