Exploring endoperoxides as a new entry for the synthesis of branched azasugars

• Svenja Domeyer,
• Mark Bjerregaard,
• Henrik Johansson and
• Daniel Sejer Pedersen

Beilstein J. Org. Chem. 2017, 13, 644–647, doi:10.3762/bjoc.13.63

• these building blocks provided access to a variety of derivatives including tetrahydrofurans, epoxides and protected amino-tetraols. Keywords: azasugar; carbohydrate; cycloaddition; endoperoxide; photochemistry; Introduction Azasugars are small organic compounds that can mimic carbohydrates or their

• in treatment of type I Gaucher’s disease and Niemann Pick type C disease (Scheme 1). Historically, azasugars were most commonly synthesised from available carbohydrate starting materials, a strategy that is still extensively employed today [4][5]. However, a variety of alternative synthetic

Biosynthetic origin of butyrolactol A, an antifungal polyketide produced by a marine-derived Streptomyces

• Enjuro Harunari,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2017, 13, 441–450, doi:10.3762/bjoc.13.47

• /carbohydrate/nucleic acid derivatives [1][2]. One of the largest groups of bacterial secondary metabolites is polyketide from which a range of clinically used drugs have been developed. Polyketides still remain in the focus of drug development because of their structural complexity that can provide attractive

Total synthesis of a Streptococcus pneumoniae serotype 12F CPS repeating unit hexasaccharide

• Peter H. Seeberger,
• Claney L. Pereira and
• Subramanian Govindan

Beilstein J. Org. Chem. 2017, 13, 164–173, doi:10.3762/bjoc.13.19

• ] strategy that was not successful due to steric constraints. The synthetic hexasaccharide is the starting point for further immunological investigations. Keywords: carbohydrate antigen; glycosylation; oligosaccharides; Streptococcus pneumoniae; total synthesis; Introduction Streptococcus pneumoniae is a

• polysaccharides (CPS) that surround them, are responsible for about 90% of infections worldwide [7]. The licensed polysaccharide vaccine Pneumovax 23 contains serotype 12F but is not efficacious in young children or elderly people, those at highest risk. The carbohydrate conjugate vaccines Prevanar13™ and

Silyl-protective groups influencing the reactivity and selectivity in glycosylations

• Mikael Bols and
• Christian Marcus Pedersen

Beilstein J. Org. Chem. 2017, 13, 93–105, doi:10.3762/bjoc.13.12

• silylene protective groups are also becoming increasingly popular. In carbohydrate chemistry silyl protective groups have frequently been used primarily as an orthogonal protective group to the more commonly used acyl and benzyl protective groups. However, silyl protective groups have significantly

• or high stereoselectivity. This mini review will summarize these findings. Keywords: Carbohydrate; conformation; glycosylation; reactivity; selectivity; Introduction Silicon-based protective groups of alcohols have a long history in organic chemistry [1][2][3]. The most popular and commercially

• available silyl-protective groups are trimethylsilyl (TMS), triethylsilyl (TES), tert-butyldimethylsilyl (TBS), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS) as well as the diol-protective groups DTBS and TIPDS (Figure 1). Silyl groups have also early been used in the carbohydrate field to

Iodination of carbohydrate-derived 1,2-oxazines to enantiopure 5-iodo-3,6-dihydro-2H-1,2-oxazines and subsequent palladium-catalyzed cross-coupling reactions

• Michal Medvecký,
• Igor Linder,
• Luise Schefzig,
• Hans-Ulrich Reissig and
• Reinhold Zimmer

Beilstein J. Org. Chem. 2016, 12, 2898–2905, doi:10.3762/bjoc.12.289

• Michal Medvecky Igor Linder Luise Schefzig Hans-Ulrich Reissig Reinhold Zimmer Freie Universität Berlin, Institut für Chemie und Biochemie, Takustrasse 3, D-14195 Berlin, Germany 10.3762/bjoc.12.289 Abstract Iodination of carbohydrate-derived 3,6-dihydro-2H-1,2-oxazines of type 3 using iodine and

• studied syntheses and applications of 3,6-dihydro-2H-1,2-oxazines of type 3 [1][2]. These N,O-heterocycles are easily prepared in enantiopure form by a stereodivergent [3 + 3] cyclization of carbohydrate-derived nitrones 2 and lithiated alkoxyallenes 1 (Scheme 1) [3][4]. Subsequently we investigated

• -alkoxy-γ-amino-aldehydes and ketones [14]. In this context, a series of publications of our group reported on syntheses of carbohydrate mimetics [15][16][17][18][19][20] that are based on aminopyrans, aminooxepanes or other aminopolyols and that were examined for example as ligands of L- and P-selectin

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

• carbohydrate epitopes with O-alkylated ring hydroxy groups. In this context, we report the first synthesis of an O-methylated selenoglycoside, specifically methyl 2-O-methyl-L-selenofucopyranoside, a ligand of the lectin tectonin-2 from the mushroom Laccaria bicolor. The synthetic route required a strategic

• : carbohydrate chemistry; fucose; lectin; selenoglycoside; Introduction Since the discovery of seleno mercaptan by Siemens in 1847 [1], organoselenium compounds have attracted high attention. Besides their biological and pharmaceutical relevance, e.g., selenocysteine or ebselen [2][3][4][5], selenium-containing

• complex with selenium-containing ligands can enable the phase determination without the need for recombinant incorporation of amino acid analogues. Buts et al. first reported the use of a selenoglycoside as ligand for a carbohydrate-binding protein, and its use for X-ray crystallographic structure

Orthogonal protection of saccharide polyols through solvent-free one-pot sequences based on regioselective silylations

• Serena Traboni,
• Emiliano Bedini and
• Alfonso Iadonisi

Beilstein J. Org. Chem. 2016, 12, 2748–2756, doi:10.3762/bjoc.12.271

• ), although, as shown earlier in Table 2, entry 4, direct silylation of the same precursor was quite unfruitful. Conclusion In the first part of this paper we have introduced a very simple approach to carry out the selective TBDMS or TBDPS protection of carbohydrate polyols taking advantage of reactions

Benzothiadiazole oligoene fatty acids: fluorescent dyes with large Stokes shifts

• Lukas J. Patalag and
• Daniel B. Werz

Beilstein J. Org. Chem. 2016, 12, 2739–2747, doi:10.3762/bjoc.12.270

• as the carbohydrate part of glycolipids [7][8]. A further alternative is to render the lipid and especially the fatty acid part fluorescently active by the introduction of fluorescent moieties (Figure 1). Prominent examples in this area are NBD- (nitrobenzoxadiazole) [9][10], BODIPY- (boron

Enzymatic synthesis and phosphorolysis of 4(2)-thioxo- and 6(5)-azapyrimidine nucleosides by E. coli nucleoside phosphorylases

• Vladimir A. Stepchenko,
• Anatoly I. Miroshnikov,
• Frank Seela and
• Igor A. Mikhailopulo

Beilstein J. Org. Chem. 2016, 12, 2588–2601, doi:10.3762/bjoc.12.254

• transglycosylation reaction of the corresponding thioxopyrimidines employing thymidine as a donor of the carbohydrate residue and E. coli TP as a biocatalyst [35]; 6-azauracil (3a) and 6-azathymine (4a) displayed no substrate activity in analogous reactions (cf. [26][27][28][29]). These studies prompted us to

Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

• Laszlo Jicsinszky,
• Marina Caporaso,
• Katia Martina,
• Emanuela Calcio Gaudino and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2016, 12, 2364–2371, doi:10.3762/bjoc.12.230

• simplicity and flexibility [18][19][20][21]. While the mechanochemical manipulation of covalent bonds is hardly a brand new concept, its diffusion into carbohydrate chemistry, and particularly into CD derivatization, has been rather slow [22][23]. The ability of HEBM to favour the nucleophilic substitution

Useful access to enantiomerically pure protected inositols from carbohydrates: the aldohexos-5-uloses route

• Felicia D’Andrea,
• Giorgio Catelani,
• Lorenzo Guazzelli and
• Venerando Pistarà

Beilstein J. Org. Chem. 2016, 12, 2343–2350, doi:10.3762/bjoc.12.227

• the stereoselective synthesis of enantiopure inositol derivatives, also the possibility to pick and tag specific positions of the inositol ring, installing the protective groups earlier on the carbohydrate frame through the well-known sugar chemistry, is of extreme interest. Although some attractive

Isosorbide and dimethyl carbonate: a green match

• Fabio Aricò and
• Pietro Tundo

Beilstein J. Org. Chem. 2016, 12, 2256–2266, doi:10.3762/bjoc.12.218

• reactivity of isosorbide and the non-toxic properties of DMC represent indeed a green match leading to several industrial appealing potential applications. Keywords: carbohydrate chemistry; D-sorbitol; dimethyl carbonate; green chemistry; isosorbide; Review Introduction In the last twenty years biorefinery

Superelectrophilic activation of 5-hydroxymethylfurfural and 2,5-diformylfuran: organic synthesis based on biomass-derived products

• Dmitry S. Ryabukhin,
• Dmitry N. Zakusilo,
• Mikhail O. Kompanets,
• Anton A.Tarakanov,
• Irina A. Boyarskaya,
• Tatiana O. Artamonova,
• Mikhail A. Khohodorkovskiy,
• Iosyp O. Opeida and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2016, 12, 2125–2135, doi:10.3762/bjoc.12.202

• ; Introduction Nowadays great attention is paid to the use of renewable resources for obtaining fine chemicals and fuels (see numerous reviews [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]). The biorefinery of renewable lignin-carbohydrate materials affords various low-molecular weight organic

The direct oxidative diene cyclization and related reactions in natural product synthesis

• Juliane Adrian,
• Leona J. Gross and
• Christian B. W. Stark

Beilstein J. Org. Chem. 2016, 12, 2104–2123, doi:10.3762/bjoc.12.200

• (6) (Scheme 4). It was also possible to produce another carbohydrate using the same synthetic pathway. Thus, mono-protection of THF diol 5 followed by oxidation of the remaining free primary hydroxy group to the carboxylic acid and a final hydrogenolysis gave (+)-D-chitaric acid (7) with a yield of

p-Nitrophenyl carbonate promoted ring-opening reactions of DBU and DBN affording lactam carbamates

• Madhuri Vangala and
• Ganesh P Shinde

Beilstein J. Org. Chem. 2016, 12, 2086–2092, doi:10.3762/bjoc.12.197

• carbohydrate–protein interactions [25], ligation and surfactant properties [26][27]. Although p-nitrophenyl carbonates were extensively utilized in these reactions, the nucleophilicity of amidine bases towards these carbonates was not encountered so far. In continuation of our interest in carbohydrates [28][29

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• Asymmetric (chiral) hetero-Diels–Alder reactions in a stereoselective (enantioselective or diastereoselective) manner have become very popular in the last decade. Pioneering works by Kresze and Vasella [56][94][105] using carbohydrate-based α-chloronitroso agents and Kirby [14] using acylnitroso compounds

Synthesis and NMR studies of malonyl-linked glycoconjugates of N-(2-aminoethyl)glycine. Building blocks for the construction of combinatorial glycopeptide libraries

• Markus Nörrlinger,
• Sven Hafner and
• Thomas Ziegler

Beilstein J. Org. Chem. 2016, 12, 1939–1948, doi:10.3762/bjoc.12.183

• , investigating the delicate carbohydrate–protein interactions on a molecular level is an inalienable prerequisite for a deep understanding of the fundamental cellular recognition processes involving the complex saccharides of the glycocalyx [5][6][7][8]. Unfortunately, isolation of pure carbohydrate material or

From supramolecular chemistry to the nucleosome: studies in biomolecular recognition

• Marcey L. Waters

Beilstein J. Org. Chem. 2016, 12, 1863–1869, doi:10.3762/bjoc.12.175

• (after Sara Butterfield) [33], Sarah–Zachtide – which investigates a carbohydrate–π interaction (after Sarah Kiehna and Zachary Laughrey) [27][28], Bobtide – which contains a cation–π interaction with KMe3 (trimethyllysine) and was the most stable β-hairpin reported at the time (after Robert Hughes) [22

Synthesis of the C8’-epimeric thymine pyranosyl amino acid core of amipurimycin

• Pramod R. Markad,
• Navanath Kumbhar and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2016, 12, 1765–1771, doi:10.3762/bjoc.12.165

• ; carbohydrate; peptidyl nucleosides; Introduction Peptidyl nucleoside antibiotics are a class of complex molecules that encompass an extensive array of natural products [1]. The notable structural features of peptidyl nucleosides are responsible for their miscellaneous biological activities such as antitumor

• of 1 is not known. The reported methodologies are mainly focused on construction of the exigent central pyranosyl amino acid fragment with or without the C3’-branched chain and nucleobase, frequently using carbohydrate substrate [6][7][8][9][10][11][12][13][14][15]. In a non-carbohydrate approach

• , Garner and co-workers have exploited a cycloaddition pathway between a poly-oxygenated diene and Garner’s aldehyde for constructing the carbohydrate core of amipurimycin [9]. Recently, Datta and co-workers reported the first synthesis of a fully-functionalized thymine analogue of amipurimycin, utilizing

Automated glycan assembly of a S. pneumoniae serotype 3 CPS antigen

• Markus W. Weishaupt,
• Stefan Matthies,
• Mattan Hurevich,
• Claney L. Pereira,
• Heung Sik Hahm and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2016, 12, 1440–1446, doi:10.3762/bjoc.12.139

• serotype 3 oligosaccharides have been developed and were applied to other uronic acid containing carbohydrate structures [21][22]. The first method uses only glucose building blocks to assemble oligosaccharides and introduces the C6 carboxylic acid moieties via a late-stage oxidation. Using this method

• conclusion, we have developed an efficient method for the synthesis of S. pneumoniae serotype 3 CPS structures. The products of these syntheses are currently used in the development of synthetic carbohydrate conjugate vaccines. Disaccharide repeating unit of the S. pneumoniae serotype 3 CPS. Building blocks

Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

• Barbara Dmochowska,
• Karol Sikora,
• Anna Woziwodzka,
• Jacek Piosik and
• Beata Podgórska

Beilstein J. Org. Chem. 2016, 12, 1434–1439, doi:10.3762/bjoc.12.138

• . The polymers (oligosaccharides) of D-glucose found, for example, in wood (cellulose) and D-glucosamine present in shells of crabs and insects (chitin), are the widely known ones [1][2]. Another class of carbohydrate biopolymer derivatives – D-ribose and 2-deoxy-D-ribose – constitutes the backbone of

• observations on the pronounced mutagenic activity of QAS derivatives with two carbon atom spacers dividing the sugar moiety and the ammonium group [22], we investigated the mutagenic activity of newly synthesized QAS with a carbohydrate spacer containing six carbon atoms. Two different bacterial mutagenicity

• containing a carbohydrate moiety with a two-carbon atom linker in the Vibrio harveyi bioluminescence assay. Here, we provide evidence for the mutagenic potential of corresponding QAS–carbohydrate derivatives with a longer, six-carbon atom linker. This suggests that the introduction of a longer hydrocarbon

A robust synthesis of 7,8-didemethyl-8-hydroxy-5-deazariboflavin

• Matthias Bender,
• Henrik Mouritsen and
• Jens Christoffers

Beilstein J. Org. Chem. 2016, 12, 912–917, doi:10.3762/bjoc.12.89

• carbohydrate chemistry and might then allow purification and characterization of intermediate products. While we were following the synthetic approach by Yoneda et al. with a protected ribose derivative, Foss and co-workers were obviously facing the same preparative problem. To our surprise and delight (that

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

• Background: Derivatives of D-glucosamine and D-galactosamine represent an important family of the cell surface glycan components and their fluorinated analogs found use as metabolic inhibitors of complex glycan biosynthesis, or as probes for the study of protein–carbohydrate interactions. This work is

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

• Elena N. Sigida,
• Yuliya P. Fedonenko,
• Alexander S. Shashkov,
• Nikolay P. Arbatsky,
• Evelina L. Zdorovenko,
• Svetlana A. Konnova,
• Vladimir V. Ignatov and
• Yuriy A. Knirel

Beilstein J. Org. Chem. 2016, 12, 636–642, doi:10.3762/bjoc.12.62

• carbohydrate and glycolipid parts [15] followed by fractionation of the released water-soluble carbohydrate portion by Sephadex G-50 Superfine size-exclusion chromatography. It was demonstrated that the OPS contained 2-O-methyl-6-deoxyhexose, L-rhamnose (Rha), D-fucose (Fuc), D-xylose (Xyl), and D-glucose (Glc

Biosynthesis of α-pyrones

• Till F. Schäberle

Beilstein J. Org. Chem. 2016, 12, 571–588, doi:10.3762/bjoc.12.56

• a ppyS homologue. However, instead of the syntenic genomic region where pseudomonads usually harbor the ppyS homologue, it appeared that the gene has inserted between genes belonging to carbohydrate metabolism in P. putida BW11M1. An in-frame deletion mutant of the ppyS homologue was constructed and