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

• . These observations are consistent with the recently reported instability of O-acylated GlcNAc under basic conditions due to elimination reactions of transient hemiacetal intermediates [38]. This instability of amino sugar hemiacetals underscores the requirement to both protect the anomeric position with

• resulting from the low stability of amino sugar hemiacetals. The prepared polyfluorinated thiodonors and hemiacetals are valuable intermediates in oligosaccharide synthesis and their utility in glycosylation is currently being studied in our group. Retrosynthetic analysis of the target fluoro analogs

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

A stereoselective and flexible synthesis to access both enantiomers of N-acetylgalactosamine and peracetylated N-acetylidosamine

• Bettina Riedl and
• Walther Schmid

Beilstein J. Org. Chem. 2018, 14, 856–860, doi:10.3762/bjoc.14.71

• relationship studies. Several strategies for the synthesis of 2-amino sugars have been published so far. In one exemplary straightforward approach, GalNAc was prepared by inverting the stereogenic center at the C-4 position of N-acetylglucosamine (GlcNAc) [10]. However, the necessity of using a 2-amino sugar

• of the four desired stereogenic centers. By extending compound 5 via a Horner–Wadsworth–Emmons (HWE) reaction [15] and subsequent stereoselective introduction of the corresponding nitrogen functionality, a route to four different 2-amino sugar stereoisomers has been elaborated. Results and Discussion

Diosgenyl 2-amino-2-deoxy-β-D-galactopyranoside: synthesis, derivatives and antimicrobial activity

• Henryk Myszka,
• Patrycja Sokołowska,
• Agnieszka Cieślińska,
• Andrzej Nowacki,
• Maciej Jaśkiewicz,
• Wojciech Kamysz and
• Beata Liberek

Beilstein J. Org. Chem. 2017, 13, 2310–2315, doi:10.3762/bjoc.13.227

• the condensation of saccharides with ureas or the reaction of glycosylamines, amino sugar, or aminoglycosides with isocyanates, or their equivalents such as carbamates [32][33]. Ureido saponins presented here were obtained in the reaction of ethyl isocyanate (8), chloroethyl isocyanate (9) and phenyl

1,3-Dibromo-5,5-dimethylhydantoin as promoter for glycosylations using thioglycosides

• Fei-Fei Xu,
• Claney L. Pereira and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2017, 13, 1994–1998, doi:10.3762/bjoc.13.195

• group at C-6 and C-4 position, respectively. The DBDMH/TfOH system activates glycosyl donors including neutral monosaccharides of different configurations (D-gluco 5 and 6, D-galacto 1 and 4, D-manno 8, L-rhamno 9), amino sugar 7 and uronic acid 10. All thioglycosides reacted equally well, irrespective

Aqueous semisynthesis of C-glycoside glycamines from agarose

• Juliana C. Cunico Dallagnol,
• Alexandre Orsato,
• Diogo R. B. Ducatti,
• Miguel D. Noseda,
• Maria Eugênia R. Duarte and
• Alan G. Gonçalves

Beilstein J. Org. Chem. 2017, 13, 1222–1229, doi:10.3762/bjoc.13.121

• -anhydro-α-L-galactopyranose unit (naturally present in the agarose structure) to all glycamines synthesized, constituting an amino-substituted C-threofuranoside moiety, which is closely related to (+)-muscarine. Keywords: amino sugar; 3,6-anhydro-α-L-galactopyranose; polysaccharide (agar); protecting

• exchange resin, which by eliminating acetate ions enabled the elimination of remaining ammonia by reduced pressure evaporation. The amino sugar rich fraction was then concentrated and chromatographed on silica gel using MeOH/2 M NH4OH as mobile phase. An aqueous solution containing the isolated free-base

• ). By performing the reductive amination between 2 and dimethylamine hydrochloride we obtained a mixture of epimers (8 and epi-8) which differed on the stereochemistry of the C-2 of the 3,6-anhydro amino sugar moiety. This was related to the fact that during the course of the reductive amination, the

Enduracididine, a rare amino acid component of peptide antibiotics: Natural products and synthesis

• Darcy J. Atkinson,
• Briar J. Naysmith,
• Daniel P. Furkert and
• Margaret A. Brimble

Beilstein J. Org. Chem. 2016, 12, 2325–2342, doi:10.3762/bjoc.12.226

• 75. Coupling of 75 with amino sugar 76 and global deprotection afforded minosaminomycin (9) in three steps from enduracididine (1). It should be noted that the diastereomer (2R-isomer) of 9 was also synthesised starting from D-enduracididine. Biological testing of both compounds revealed that the 2R

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

• Daniel Wiegmann,
• Stefan Koppermann,
• Marius Wirth,
• Giuliana Niro,
• Kristin Leyerer and
• Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

• glycosylated in its 5'-position with an aminoribose unit and in some cases a lipophilic side chain is attached to the hydroxyleucine residue. The 19 compounds are divided into four different series (A–D) which mainly vary in the leucine residue and the lipophilic side chain or the amino sugar (Figure 1). The

Synthesis and in vitro cytotoxicity of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine

• Štěpán Horník,
• Lucie Červenková Šťastná,
• Petra Cuřínová,
• Jan Sýkora,
• Kateřina Káňová,
• Roman Hrstka,
• Ivana Císařová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2016, 12, 750–759, doi:10.3762/bjoc.12.75

• -2-azido-hexopyranoses have potential as synthons in oligosaccharide assembly. Keywords: amino sugars; cytotoxicity; fluorinated carbohydrates; fluorine; hexosamines; Introduction Derivatives of D-glucosamine (GlcN) and D-galactosamine (GalN) are essential amino sugar components of glycans in

• glycan and glycosaminoglycan biosynthesis [2][3], to inhibit amino sugars processing enzymes [4][5], to probe interactions of amino sugars with their target enzymes and lectins [6][7], or to increase the hydrolytic stability of the glycosidic bond in amino sugar glycosides [8][9]. For example, acetylated

Synthesis of rigid p-terphenyl-linked carbohydrate mimetics

• Maja Kandziora and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 1749–1758, doi:10.3762/bjoc.10.182

• -allene. The Lewis acid-induced rearrangement of this heterocycle provided the corresponding bicyclic 1,2-oxazine derivative that may be regarded as internally protected amino sugar analogue. After subsequent reduction of the carbonyl group, the resulting bicyclic compound was used for Suzuki cross

• promising route to differently substituted 1,2-oxazines, introducing the dioxolane substituent at a late stage. The Lewis acid-induced rearrangement of the 1,2-oxazine 4 afforded the bicyclic ketone 11 which can be regarded as an internally protected amino sugar. After subsequent reduction of the carbonyl

Electrochemical generation of 2,3-oxazolidinone glycosyl triflates as an intermediate for stereoselective glycosylation

• Toshiki Nokami,
• Akito Shibuya,
• Yoshihiro Saigusa,
• Shino Manabe,
• Yukishige Ito and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2012, 8, 456–460, doi:10.3762/bjoc.8.52

• temperatures. However, α-selectivity was observed in the absence of base at elevated reaction temperatures. In situ generated triflic acid promotes the isomerization of β-products to α-products. Keywords: amino sugar; anomerization; electrochemical oxidation; glycosylation; thioglycoside; Introduction

Amine-linked diglycosides: Synthesis facilitated by the enhanced reactivity of allylic electrophiles, and glycosidase inhibition assays

• Ian Cumpstey,
• Jens Frigell,
• Elias Pershagen,
• Tashfeen Akhtar,
• Elena Moreno-Clavijo,
• Inmaculada Robina,
• Dominic S. Alonzi and
• Terry D. Butters

Beilstein J. Org. Chem. 2011, 7, 1115–1123, doi:10.3762/bjoc.7.128

• reaction was much less regioselective than the Mitsunobu couplings. Moreover, the major regioisomer in the palladium-catalysed reaction was the 2-amino sugar, whereas in the Mitsunobu reactions, the 4-amino sugars were formed exclusively. A small amount of stereochemical scrambling of an intermediate π

Addition of lithiated enol ethers to nitrones and subsequent Lewis acid induced cyclizations to enantiopure 3,6-dihydro-2H-pyrans – an approach to carbohydrate mimetics

• Fabian Pfrengle and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2010, 6, No. 75, doi:10.3762/bjoc.6.75

• ketones. This strategy allowed a simple access to unusual carbohydrates with C2-branched 4-amino sugar units and related carbohydrate mimetics [3][4][5][6][7]. Moreover, pursuing a similar strategy, we described the stereocontrolled preparation of 3,6-dihydro-2H-pyrans D as precursors for the synthesis of