Synthesis of multiply fluorinated N-acetyl-D-glucosamine and D-galactosamine analogs via the corresponding deoxyfluorinated glucosazide and galactosazide phenyl thioglycosides

• Vojtěch Hamala,
• Lucie Červenková Šťastná,
• Martin Kurfiřt,
• Petra Cuřínová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2021, 17, 1086–1095, doi:10.3762/bjoc.17.85

• . Conversion of 1,6-anhydro derivatives into thioglycosides, and a possible mechanism for the formation of C-furanosides by ring contraction. Deoxyfluorination and O-benzylation of thioglycosides and thioaglycone migration. Thioglycoside hydrolysis. Synthesis of the target compounds by azide/acetamide

Influence of per-O-sulfation upon the conformational behaviour of common furanosides

• Alexey G. Gerbst,
• Vadim B. Krylov,
• Dmitry A. Argunov,
• Maksim I. Petruk,
• Arsenii S. Solovev,
• Andrey S. Dmitrenok and
• Nikolay E. Nifantiev

Beilstein J. Org. Chem. 2019, 15, 685–694, doi:10.3762/bjoc.15.63

• . Lomonosov Moscow State University, Moscow, 119991, Russia 10.3762/bjoc.15.63 Abstract The studies on the recently discovered pyranoside-into-furanoside rearrangement have led us to conformational investigations of furanosides upon their total sulfation. Experimental NMR data showed that in some cases

• drastic changes of the ring conformation occurred while sometimes only the conformation of the exocyclic C4–C5 linkage changed. Herein we describe a combined quantum chemical and NMR conformational investigation of three common monosaccharide furanosides as their propyl glycosides: α-mannose, β-glucose

• of sulfates. Keywords: ab initio calculations; conformational analysis; furanosides; NMR; sulfation; Introduction Changes in the conformations of monosaccharides expectedly accompany their modification with different functional groups. Thus, spatial repulsion of silyl groups results in inversion or

Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

• Mikhail V. Makarov and
• Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

• be performed in slightly basic media, such as saturated sodium bicarbonate solution [19][31]. 3.2. Protection of 2′,3′-hydroxy groups As it is the case for most synthetic efforts associated with nucleosides’ syntheses the protection of the 2′,3′-hydroxy groups of the furanosides is required when

D-Fructose-based spiro-fused PHOX ligands: synthesis and application in enantioselective allylic alkylation

• Michael R. Imrich,
• Jochen Kraft,
• Cäcilia Maichle-Mössmer and
• Thomas Ziegler

Beilstein J. Org. Chem. 2018, 14, 2082–2089, doi:10.3762/bjoc.14.182

• is the Ritter reaction of suitable carbohydrate derivatives with nitriles under Lewis-acidic conditions [29][30][31]. Recently, Vangala and Shinde reported the synthesis of spirocyclic 2-substituted 2-oxazoline ribosides from 1,2-isopropylidene-protected furanosides [32]. In our case, however, only

Anomeric modification of carbohydrates using the Mitsunobu reaction

• Julia Hain,
• Patrick Rollin,
• Werner Klaffke and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138

• glycosylation, Grochowski explored the synthesis of new nucleoside analogues. 1-Hydroxy-benzotriazole, 1-hydroxy-2-cyanobenzimidazole, 1-hydroxyuracil, and 1-hydroxythymine were used to prepare the respective NO-furanosides in the manno- and ribo-series [115][116][117]. Miscellaneous The Mitsunobu reaction was

AuBr₃-catalyzed azidation of per-O-acetylated and per-O-benzoylated sugars

• Jayashree Rajput,
• Srinivas Hotha and
• Madhuri Vangala

Beilstein J. Org. Chem. 2018, 14, 682–687, doi:10.3762/bjoc.14.56

• effect of the ester groups. In a recently reported gold(III)-mediated reaction Vankar and co-workers disclosed that a AuCl3–phenylacetylene complex promotes the O-glycosylation of armed 1-O-acetyl pyranosides and furanosides [17][27]. The authors also observed that 5 mol % AuCl3 alone promoted the O

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

• the pyranose was observed in any instance. In a 2007 follow-up study, Plusquellec and colleagues optimized a Lewis-acid-directed glycosylation approach in the presence of divalent cations to synthesize galactosyl furanosides using the same thioimidoyl-activating group. The optimized conditions (Table

• furanosides. These may find application as enzyme substrates and possibly as inhibitors in several bacterial diseases, as well as in solid-phase-oligosaccharide synthesis, as shown. However, the main drawback is still the multistep synthesis of these anomeric activating donors. 3.2 Self-activation of the

Nucleophilic displacement reactions of 5′-derivatised nucleosides in a vibration ball mill

• Olga Eguaogie,
• Patrick F. Conlon,
• Francesco Ravalico,
• Jamie S. T. Sweet,
• Thomas B. Elder,
• Louis P. Conway,
• Marc E. Lennon,
• David R. W. Hodgson and
• Joseph S. Vyle

Beilstein J. Org. Chem. 2017, 13, 87–92, doi:10.3762/bjoc.13.11

• )ribofuranoside are frequently observed during both activation [7] and subsequent displacement reactions [8][9]. This competition confounds the kind of systematic analysis developed recently by Hale and co-workers for sulfonate displacement from furanosides [10] and convoluted optimisations of reaction conditions

O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

• Roman Sommer,
• Dirk Hauck,
• Annabelle Varrot,
• Anne Imberty,
• Markus Künzler and
• Alexander Titz

Beilstein J. Org. Chem. 2016, 12, 2828–2833, doi:10.3762/bjoc.12.282

• ] or plant natural products [41]. In order to optimize the synthesis of 3 by avoiding the formation of the furanose acetate 10 and increasing the α-selectivity, we revised our synthetic approach. The problematic formation of furanosides has been reported by Kovac et al. for xylose derivatives bearing a

Mycothiol synthesis by an anomerization reaction through endocyclic cleavage

• Shino Manabe and
• Yukishige Ito

Beilstein J. Org. Chem. 2016, 12, 328–333, doi:10.3762/bjoc.12.35

• glycolipids [35][36][37]. Sulfated sugars are isomerized from pyranosides to furanosides [38]. The anomerization reaction would be a useful methodology to prepare 1,2-cis-glycosides such as heparin and glycosylphosphatidylinositol (GPI) anchors. Structure of mycothiol 1. Detoxification pathway mediated by MSH

Investigation of acetyl migrations in furanosides

• O. P. Chevallier and
• M. E. Migaud

Beilstein J. Org. Chem. 2006, 2, No. 14, doi:10.1186/1860-5397-2-14

• moiety. The synthesis of such compounds requires access to well-characterised acetylated xylose, arabinose and ribose synthetic precursors and while few acetylated furanosides have been reported in the literature, those that have, have often been obtained in modest yields and reliable compound

• acetylated ADPR analogues, unequivocally, the free C5-hydroxyl derivatives of the monoacetylated furanosides must be obtained without rearrangement upon protecting group manipulation. Consequently, it was decided to carefully characterise all possible rearrangement products occurring in acetylated furanoside

• precursors. To the best of our knowledge, acyl migrations occurring under such mild reaction conditions in furanosides has not been investigated in contrast with the extensive work that has been carried out on pyranosides.[12][13][14][15] Therefore, an investigation on the mechanisms, reaction conditions and