title: The use of O-trifluoroacetyl protection and profound influence of the nature of glycosyl acceptor in benzyl-free arabinofuranosylation.
abstract: The influence of O-trifluoroacetyl (TFA) groups at different positions of thioglycoside glycosyl donors on stereoselectivity of α-arabinofuranosylation leading to corresponding disaccharides was studied. It was shown that TFA group in thioglycoside glycosyl donors, when combined with 2-O-(triisopropylsilyl) (TIPS) non-participating group, may be regarded as an electron-withdrawing protecting group that may enhance 1,2-cis-selectivity in arabinofuranosylation, the results strongly depending on the nature of glycosyl acceptor. The reactivities of the glycosyl donors were compared with those of a similar thioglycoside with O-pentafluoropropionyl groups and the known phenyl 3,5-O-(di-tert-butylsilylene)-1-thio-α-d-arabinofuranosides with 2-O-TIPS and 2-O-benzyl groups. The 'matching' in the donor-acceptor combination was found to be critical for achieving both high reactivity of glycosyl donor and β-stereoselectivity of arabinofuranosylation. The use of glycosyl donors with TFA and silyl protection may be useful in the realization of the benzyl-free approach to oligoarabinofuranosides with azido group in aglycon-convenient building blocks for the preparation of neoglycoconjugates.
authors: N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky prosp., 47, 119991 Moscow, Russian Federation.
authors: Polina I
authors: PI
authors: Abronina
authors: N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky prosp., 47, 119991 Moscow, Russian Federation; Higher Chemical College of the Russian Academy of Sciences, Miusskaya pl. 9, 125047 Moscow, Russian Federation.
authors: Ksenia G
authors: KG
authors: Fedina
authors: N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky prosp., 47, 119991 Moscow, Russian Federation.
authors: Nikita M
authors: NM
authors: Podvalnyy
authors: N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky prosp., 47, 119991 Moscow, Russian Federation.
authors: Alexander I
authors: AI
authors: Zinin
authors: N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky prosp., 47, 119991 Moscow, Russian Federation.
authors: Alexander O
authors: AO
authors: Chizhov
authors: N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky prosp., 47, 119991 Moscow, Russian Federation.
authors: Nikolay N
authors: NN
authors: Kondakov
authors: N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky prosp., 47, 119991 Moscow, Russian Federation.
authors: Vladimir I
authors: VI
authors: Torgov
authors: N.D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky prosp., 47, 119991 Moscow, Russian Federation. Electronic address: kononov@ioc.ac.ru.
authors: Leonid O
authors: LO
authors: Kononov
mesh_terms: D001089:Arabinose / Q000031:analogs & derivatives* / Q000737:chemistry; D004187:Disaccharides / Q000138:chemical synthesis*; D005463:Fluoroacetates / Q000737:chemistry*; D006031:Glycosylation; D013237:Stereoisomerism
chemical_list: D004187:Disaccharides; D005463:Fluoroacetates; C431714:arabinofuranose; D001089:Arabinose
keywords: 1,2-cis-Stereoselectivity; Arabinofuranose; Benzyl-free approach; Electron-withdrawing protecting groups; O-Trifluoroacetyl group