18685-22-8Relevant articles and documents
A highly efficient d-fructofuranosylation catalyzed by scandium(III) triflate
Yamanoi, Takashi,Misawa, Noriko,Watanabe, Mikio
, p. 6458 - 6462 (2007)
This Letter describes a highly efficient d-fructofuranosylation catalyzed by scandium(III) triflate. The benzylated and benzoylated d-fructofuranosyl acetate derivatives worked as good reactive donors in the presence of only 5 mol % scandium(III) triflate
Synthesis of raffinose family oligosaccharides by regioselective de-O-benzylation with Co2(CO)8/Et3SiH/CO system
Zhao, Yue-Tao,Niu, Shan,Huang, Lu-Bai,Wang, Ji-Ming,Yin, Zhao-Jun,Li, Qing,Li, Zhong-Jun
, p. 5022 - 5028 (2013/06/27)
A convenient approach for synthesis of raffinose, stachyose, and verbascose using sucrose as the starting material is presented. The key step is the regioselective de-O-benzylation with Co2(CO)8/Et 3SiH/CO system, followed by a high α-selective glycosylation. The newly developed de-O-benzylation system is efficient in removing the primary benzyl groups of sucrose and raffinose under mild condition and with high selectivity. Using thioglycoside as donor, NIS/AgOTf as promoter and DTBMP as additive, glycosylation of acid labile sucrose substrate is achieved in high yield.
Preparation of partially benzylated mono-, di-, and trisaccharides by selective cleavage of the β-fructofuranosidic linkage in fully benzylated sucrose and sucrose-related oligosaccharides under acidic conditions
Yamanoi, Takashi,Misawa, Noriko,Matsuda, Sho,Watanabe, Mikio
, p. 1366 - 1372 (2008/09/21)
Several partially benzylated mono-, di-, and trisaccharides having an anomeric hydroxyl group were successfully prepared by selective cleavage of the β-fructofuranosidic linkage in fully benzylated sucrose and sucrose-related oligosaccharides derived from lactosucrose, raffinose, melezitose, stachyose, and nystose under acidic conditions using 1:10 75% aqueous sulfuric acid-dioxane at room temperature for 1 h.
Convenient syntheses of 2,3,4,6-tetra-O-alkylated D-glucose and D-galactose
Kaesbeck, Ludwig,Kessler, Horst
, p. 169 - 173 (2007/10/03)
Convenient syntheses of the 2,3,4,6-tetra-O-benzylated and -allylated D-glucopyranoses 1 and 2 and the corresponding D-galactopyranoses 3 and 4 are described. The D-glucose derivatives 1 and 2 were obtained from inexpensive sucrose by peralkylation and subsequent acid hydrolysis. In this reaction sequence an alkylated D-fructofuranosyl cation is generated which was trapped by different nucleophiles to afford 4-benzyloxymethylenefurfural (8) and the alkylated D-fructosides 7, 8 and 10. On the other hand 2,3,4,6-tetra-O-benzyl-D-galactose 3 was synthesized by oxidative cleavage of ethyl 2,3,4,6-tetra-O-benzyl-1-thio-α,β-D-galactopyranoside (11) with aqueous N-bromosuccinimide. The alternative route for the preparation of 2,3,4,6-tetra-O-allyl-D-glucopyranoside (2) via p-methoxybenzyl β-D-glucoside is less attractive. However, this route was used for the synthesis of 2,3,4,6-tetra-O-allyl-D-galactose (4). VCH Verlagsgesellschaft mbH, 1997.
Synthesis of D-fructofuranosides using thioglycosides as glycosyl donors
Krog-Jensen, Christian,Oscarson, Stefan
, p. 1234 - 1238 (2007/10/03)
Benzylated and benzoylated ethyl thioglycosides of D-fructofuranose have been synthesized and tested as glycosyl donors in couplings to various primary and secondary carbohydrate acceptors. Treatment of 2-O-acetyl-1,3,4,6-tetra-O-benzoyl-D-fructofuranose with ethyl mercaptan in a BF3·-etherate-promoted reaction gave the benzoylated ethyl 2-thio-α,β-D-fructofuranosides, which after deacylation and benzylation afforded the benzylated derivatives. These thiofructofuranosides, using dimethyl(methylthio)sulfonium triflate (DMTST) or N-iodosuccinimide as promoter, were found to be excellent donors, which gave disaccharide coupling products in quantitative or almost quantitative yields with all tested acceptors, yields rarely found in oligosaccharide synthesis. The benzoylated donors gave only α-linked fructofuranosides, due to participation of the 3-O-benzoyl group, whereas the benzylated donors gave α/β-mixtures.
Benzylation of sugar polyols by means of the PTC method
Szeja, W.,Fokt, I.,Grynkiewicz, G.
, p. 224 - 226 (2007/10/02)
Studies on benzylation of hydrophilic carbohydrate derivatives with benzyl chloride, using a phase-transfer technique, have led to the conclusion that alkylation of a substrate can be greatly facilitated by the introduction of a "co-catalyst" (e.g. a tertiary alcohol) and/or a co-solvent (e.g.DMSO) to the reaction mixture.Efficient procedures for benzylation of sugar derivatives having three to eight hydroxyl groups per molecule, in two-phase system employing an almost stoichiometric amount of the alkylating agent, are presented.
