Oligomerization of optically active N-(4-hydroxyphenyl)mandelamide in the presence of β-cyclodextrin and the minor role of chirality

• Helmut Ritter,
• Antonia Stöhr and
• Philippe Favresse

Beilstein J. Org. Chem. 2014, 10, 2361–2366, doi:10.3762/bjoc.10.246

• NMR spectroscopy because of the different induced shift of the protons which became diastereotopic through complexation [11][12]. Actually, the chirality discrimination of 1 with RAMEB-CD is evident from the different induced shift of the protons 8 at 5.2 ppm (zoomed out in Figure 1). The MALDI–TOF MS

• enzymatic oligomerization consists of up to 10 repetitive units which could be detected by MALDI–TOF MS measurements. Furthermore comparable molecular weights are accessible through oligomerization of 1 with iron(II)-salen as catalyst. Here oligomers 2 with up to 8 repetitive units are detectable. The

• 500. MALDI–TOF spectra were performed on a Bruker Ultraflex TOF mass spectrometer, the molecular masses being recorded in linear mode. Dithranol was used as a matrix and sodium trifluoroacetate (NaTFA) as ionization reagent. The samples were dissolved in DMF. DSC measurements were performed using a

Specific DNA duplex formation at an artificial lipid bilayer: fluorescence microscopy after Sybr Green I staining

• Emma Werz and
• Helmut Rosemeyer

Beilstein J. Org. Chem. 2014, 10, 2307–2321, doi:10.3762/bjoc.10.240

• -hydroxymethylpropane-1,3-diol (TRIS) were purchased from Roth (Karlsruhe, Germany). All oligonucleotides 4–10 (Figure 1) were synthesized, purified and characterized by MALDI–TOF mass spectrometry by Eurogentec SA (Liege, Belgium). In each case the detected mass confirmed the corresponding calculated mass. MALDI–TOF

Synthesis and optical properties of pyrrolidinyl peptide nucleic acid carrying a clicked Nile red label

• Nattawut Yotapan,
• Chayan Charoenpakdee,
• Pawinee Wathanathavorn,
• Boonsong Ditmangklo,
• Hans-Achim Wagenknecht and
• Tirayut Vilaivan

Beilstein J. Org. Chem. 2014, 10, 2166–2174, doi:10.3762/bjoc.10.224

• under different sequence context, were successfully synthesized and characterized by MALDI–TOF MS (Figure 1 and Table 1). Isolated yields in the range of 6–18% were obtained (0.5 μmol scale), which are typical for solid phase synthesis, whereby the majority of material loss occurred during HPLC

• temperature overnight. After the reaction was completed, the labeled acpcPNA was cleaved from the solid support with trifluoroacetic acid (500 µL × 30 min × 3). After drying and washing with diethyl ether, the residue was purified by reversed-phase HPLC and characterized by MALDI–TOF mass spectrometry

• emission at 643 nm of the single-stranded acpcPNA at the same temperature and plotted against the temperature to obtain the fluorescence melting curves. Melting temperatures were obtained from the UV or fluorescence melting curves by first derivative plots. MALDI–TOF mass spectra of the crude 10mer acpcPNA

Synthesis of phosphoramidites of isoGNA, an isomer of glycerol nucleic acid

• Keunsoo Kim,
• Venkateshwarlu Punna,
• Phaneendrasai Karri and
• Ramanarayanan Krishnamurthy

Beilstein J. Org. Chem. 2014, 10, 2131–2138, doi:10.3762/bjoc.10.220

• removing the tert-Boc group (as seen by MALDI–TOF mass spectral data in combination with ion-exchange HPLC monitoring) [8]. Improved synthesis of adenine-isoGNA building block We went back in our synthesis in order to address the adenine protecting group problem and to re-work the inefficient Mitsunobu

Synthesis of a bifunctional cytidine derivative and its conjugation to RNA for in vitro selection of a cytidine deaminase ribozyme

• Nico Rublack and
• Sabine Müller

Beilstein J. Org. Chem. 2014, 10, 1906–1913, doi:10.3762/bjoc.10.198

• stirring 16 in a 1:1 mixture of concentrated aqueous ammonia and methylamine. Subsequent treatment of 17 with triethylamine trihydrofluoride (TEA·3HF) at 55 °C for 2 h delivered compound 18, which was reacted with neat TFA. Each deprotection step was monitored by MALDI mass spectrometry. The

• derivative 1 (B), and a new peak (III) indicating the desired RNA–cytidine conjugate, as confirmed by MALDI mass spectrometry (see Supporting Information File 1). Conclusion We successfully synthesized a cytidine derivative for the functionalization of an RNA library following a synthetic route over 16 steps

• confirmed by successful conjugation to the 3'-terminus of a model RNA, as analyzed by HPLC and MALDI–MS. This set-up is going to be used for selection of a cytidine deaminase ribozyme supporting the conversion of uridine to cytidine. Active molecules will be cleaved from the solid phase and released into

The search for new amphiphiles: synthesis of a modular, high-throughput library

• George C. Feast,
• Thomas Lepitre,
• Xavier Mulet,
• Charlotte E. Conn,
• Oliver E. Hutt,
• G. Paul Savage and
• Calum J. Drummond

Beilstein J. Org. Chem. 2014, 10, 1578–1588, doi:10.3762/bjoc.10.163

• that a longer reaction time would have allowed complete conversion of the two bulky reactants into product. All amphiphiles were subjected to MALDI–TOF mass spectrometry to determine product formation, and of the 80 amphiphiles in the library, only 3 (4%) did not generate the desired mass unit

• in Table 4. All three compounds had copper contents <0.06% and, when combined with the 13C NMR and MALDI–TOF data, we were satisfied the compounds were pure enough for subsequent lyotropic phase data to be of significance in the context of a screen. The amphiphiles produced in this library are

Multivalent scaffolds induce galectin-3 aggregation into nanoparticles

• Candace K. Goodman,
• Mark L. Wolfenden,
• Pratima Nangia-Makker,
• Anna K. Michel,
• Avraham Raz and
• Mary J. Cloninger

Beilstein J. Org. Chem. 2014, 10, 1570–1577, doi:10.3762/bjoc.10.162

• functionalized dendrimers were characterized by MALDI–TOF–MS (matrix-assisted laser desorption time of flight mass spectrometry). The average numbers of sugars that were incorporated are shown in Scheme 2. The loadings were determined by both the changes in weight average molecular weight (Mw) upon addition of 1

• mg, 2.20 μmol) solution. The mixture was stirred for 8 h at which point a 75 μL aliquot was collected and lyophilized for MALDI–TOF and NMR analysis. The remainder of the reaction mixture was lyophilized and subjected to the deacetylation procedure. This procedure for carbohydrate functionalization

• , m = multiplet, app = apparent), integration, coupling constants (in Hz) and assignments. Sample NMR spectra are provided in Figures S2 through S6, Supporting Information File 1. MALDI–TOF mass spectrometry MALDI mass spectra were acquired using a Bruker Biflex-III time-of-flight mass spectrometer

Biantennary oligoglycines and glyco-oligoglycines self-associating in aqueous medium

• Svetlana V. Tsygankova,
• Alexander A. Chinarev,
• Alexander B. Tuzikov,
• Nikolai Severin,
• Alexey A. Kalachev,
• Juergen P. Rabe,
• Alexandra S. Gambaryan and
• Nicolai V. Bovin

Beilstein J. Org. Chem. 2014, 10, 1372–1382, doi:10.3762/bjoc.10.140

• chemical shifts was calibrated against the signals of residual protons of solvents (CDCl3: δ 7.26 ppm; DMSO-d6: δ 2.50 ppm; D2O: δ 4.75 ppm). Mass-spectra were recorded on the time-of-flight spectrometer Vision-2000 (Thermo Bioanalysis, UK) with MALDI with 2,6-dihydroxybenzoic acid as reference. Raman

Glycosystems in nanotechnology: Gold glyconanoparticles as carrier for anti-HIV prodrugs

• Fabrizio Chiodo,
• Marco Marradi,
• Javier Calvo,
• Eloisa Yuste and
• Soledad Penadés

Beilstein J. Org. Chem. 2014, 10, 1339–1346, doi:10.3762/bjoc.10.136

• paragraph). The ester derivatives were not detected in the EtOH washings after the GNPs precipitation (by MALDI–MS and 1H NMR) indicating that practically all the drug conjugates were linked on the gold surface. Drug quantification and release of the drug from GNPs We studied the stability of the GNPs

Automated solid-phase peptide synthesis to obtain therapeutic peptides

• Veronika Mäde,
• Sylvia Els-Heindl and
• Annette G. Beck-Sickinger

Beilstein J. Org. Chem. 2014, 10, 1197–1212, doi:10.3762/bjoc.10.118

• major prerequisite for the success of SPPS, both with respect to analytics and preparative purification [25]. Furthermore, high-quality mass spectrometry (MS) with soft ionization techniques such as MALDI–TOF (matrix-assisted laser desorption ionization – time of flight) and ESI (electrospray ionization

Solid-phase-supported synthesis of morpholinoglycine oligonucleotide mimics

• Tatyana V. Abramova,
• Sergey S. Belov,
• Yulia V. Tarasenko and
• Vladimir N. Silnikov

Beilstein J. Org. Chem. 2014, 10, 1151–1158, doi:10.3762/bjoc.10.115

• at 30 °C. Chemical shifts (δ) are reported in ppm relative to TMS signals. Coupling constants J are reported in Hertz. MALDI–TOF mass spectra were registered on an Autoflex III mass spectrometer (Bruker Daltonics, Germany) using 2,5-dihydroxybenzoic acid as a matrix (MALDI–TOF) in positive or

• (app. t, J = 10.3 Hz, 1H, H3), 2.01 (app. t, J = 10.6 Hz, 1H, H5), 1.77 (s, 3H, СН3-Thy), 1.37 (s, 9H, CH3-Boc); MALDI–TOFMS (m/z): [M + H]+ calcd for C17H27N4O7, 399.19; found, 399.77; [M + Na]+ calcd for C17H26N4NaO7, 421.17; found, 421.64. See Supporting Information File 1 for the synthetic scheme

• , 1H, H5), 2.75–2.64 (m, 2H, NH2CH2), 1.81 (d, J = 0.8 Hz, 3H, CH3), 1.39 (dd, J = 11.1, 10.0 Hz, 1H, H3), 1.35–1.30 (dd, J = 11.6, 10.6 Hz, 1H, H5); MALDI–TOFMS (m/z): [M – Tr + 2H]+ (the Tr protective group was removed during the sample preparation) calcd for C10H17N4O3 241.13; found, 241.45

Novel indolin-2-one-substituted methanofullerenes bearing long n-alkyl chains: synthesis and application in bulk-heterojunction solar cells

• Irina P. Romanova,
• Andrei V. Bogdanov,
• Inessa A. Izdelieva,
• Vasily A. Trukhanov,
• Gulnara R. Shaikhutdinova,
• Dmitry G. Yakhvarov,
• Shamil K. Latypov,
• Vladimir F. Mironov,
• Vladimir A. Dyakov,
• Ilya V. Golovnin,
• Dmitry Yu. Paraschuk and
• Oleg G. Sinyashin

Beilstein J. Org. Chem. 2014, 10, 1121–1128, doi:10.3762/bjoc.10.111

• fullerene. UV–vis, IR, and NMR spectroscopy confirmed their structure. The composition was established by MALDI–TOF mass spectrometry. Optical absorption, electrochemical properties and solubility of AIMs Figure 2 compares a typical optical absorption spectrum of AIMs with those of PCBM and pristine

• Ultraflex III MALDI TOF/TOF SYSTEM» apparatus. NMR experiments were carried out with a Bruker AVANCE-600 spectrometer (14.1 T) equipped with a pulsed gradient unit capable of producing magnetic field pulse gradients in the z-direction of 56 G·cm−1. All spectra were acquired in a 5 mm inverse probehead

Towards allosteric receptors – synthesis of β-cyclodextrin-functionalised 2,2’-bipyridines and their metal complexes

• Christopher Kremer,
• Gregor Schnakenburg and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 814–824, doi:10.3762/bjoc.10.77

• )]PF6, and [Zn(22)(1)](OTf)2 as evidenced by MALDI mass spectrometry and NMR spectroscopy (Figure 6 and Figure 7). Hence, zinc(II) ions or their complexes with a single, sterically demanding phenanthroline ligand like 22 as well as a similar [Cu(22)]+ complex were all found to be good effectors for

• : carbon, red: oxygen, blue: nitrogen, yellow: sulfur, white: hydrogen). MALDI mass spectrum (sample prepared from a 1:1 mixture of CuPF6 and 2 in benzene/acetonitrile (1:1) using DCTB (trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile) as matrix). Aromatic region of the 1H NMR spectra

• , benzene-d6/acetonitrile-d3 1:1) of a) 1, b) [Zn(22)(1)](OTf)2, and c) 22. Arrows indicate signal shifts upon formation of the heteroleptic complex. MALDI–TOF mass spectrum (sample prepared from of a 1:1:1 mixture of CuPF6, 22, and 1 in benzene/acetonitrile (1:1) using DCTB as matrix). Off- (open) and on

Staudinger ligation towards cyclodextrin dimers in aqueous/organic media. Synthesis, conformations and guest-encapsulation ability

• Malamatenia D. Manouilidou,
• Yannis G. Lazarou,
• Irene M. Mavridis and
• Konstantina Yannakopoulou

Beilstein J. Org. Chem. 2014, 10, 774–783, doi:10.3762/bjoc.10.73

• dissolution of 2 or 3 were observed evidently due to secondary reactions leading to a lower yield for the ligation step. Monomer 4 and dimer 6 displayed a single 31P NMR signal at 35.2 ppm and the correct mass in MALDI–TOF MS. Reaction of 4 with mono(6-15N-amino-6-deoxy)-β-CD under typical amide coupling

• gratefully acknowledged. A scholarship to M.D.M. by NCSR “Demokritos” is gratefully acknowledged. We also thank Mr. A. R. L. Marouvo Gonçalves of our group for preparing NDTAM·HCl. Istituto di Ricerche Chimiche e Biochimiche "G. Ronzoni" Milano, Italy, is also acknowledged for the MALDI–TOF measurements.

Thermodynamically stable [4 + 2] cycloadducts of lanthanum-encapsulated endohedral metallofullerenes

• Yuta Takano,
• Yuki Nagashima,
• M. Ángeles Herranz,
• Nazario Martín and
• Takeshi Akasaka

Beilstein J. Org. Chem. 2014, 10, 714–721, doi:10.3762/bjoc.10.65

• spectroscopic methods such as MALDI–TOF mass, optical absorption, and NMR spectroscopy. The [4 + 2] adducts of La2@C80 (3a,b, and 4a,b) and La@C82 (5b), respectively, retain diamagnetic and paramagnetic properties, as confirmed by EPR spectroscopy. Dynamic NMR measurements of 4a at various temperatures

• the cycloadducts (3a,b and 4a,b). The reactions were traced using HPLC analyses (Figure 1), and formation of the resulting [4 + 2] adducts was confirmed by matrix-assisted laser desorption ionization (MALDI) TOF mass spectrometry (Figure 2), which shows the molecular ion peaks for the corresponding

• compounds in HPLC. The mixture of 3a and 4a was first separated from the unreacted starting materials and byproducts through one-step HPLC separation. The MALDI–TOF mass spectra of 3a and 4a showed single peaks attributed to the molecular ion peak of the target molecule, La2@C80C2H4C6H4, at 1342 m/z (Figure

End-group-functionalized poly(N,N-diethylacrylamide) via free-radical chain transfer polymerization: Influence of sulfur oxidation and cyclodextrin on self-organization and cloud points in water

• Sebastian Reinelt,
• Daniel Steinke and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 680–691, doi:10.3762/bjoc.10.61

• functionalization is supported by 1H NMR-, SEC-, FTIR- and MALDI–TOF measurements. Keywords: chain-transfer polymerization; cyclodextrins; end-group functionalization; host–guest interaction; lower critical solution temperature (LCST); poly(N,N-diethylacrylamide); Introduction Supramolecular chemistry was first

• Table 1. Exemplarily, Figure 1 shows a section of the MALDI–TOF spectrum of polymer 8b confirming a high degree of 4-tert-butylphenol end-group functionalization. Just single series of peaks with a peak separation of 127.1 which corresponds to the mass of DEAAm plus the proposed end-group (224.1) and

• accomplished by oxidation with hydrogen peroxide in analogy to literature [11]. As expected, the MALDI–TOF mass spectrum for 8bOx showed only one series of peaks, which was shifted by 16 Dalton in comparison to the origin series of peaks (see Figure 3). The FTIR spectrum showed a decrease of transmission at a

Rapid pseudo five-component synthesis of intensively blue luminescent 2,5-di(hetero)arylfurans via a Sonogashira–Glaser cyclization sequence

• Fabian Klukas,
• Alexander Grunwald,
• Franziska Menschel and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 672–679, doi:10.3762/bjoc.10.60

• analyzed by MALDI–TOF mass spectrometry indicating the formation of oligomers with m/z = 422 to 1046. We could efficiently suppress this oligo- and polymerization by increasing the amount of solvent, i.e. by dilution (Table 1, entries 9–13). Additionally increasing the concentration of KOH and water also

Tuning the interactions between electron spins in fullerene-based triad systems

• Maria A. Lebedeva,
• Thomas W. Chamberlain,
• E. Stephen Davies,
• Bradley E. Thomas,
• Martin Schröder and
• Andrei N. Khlobystov

Beilstein J. Org. Chem. 2014, 10, 332–343, doi:10.3762/bjoc.10.31

• [22] and was reacted with [60]fulleropyrrolidine 9 to give the benzyl ester protected compound 11 in 68% yield. Subsequent deprotection of 11 by CF3SO3H yielded the insoluble product 12 that precluded characterisation by solution based methods. However, MALDI–MS of 12 showed a molecular ion peak with

• solubility, but MALDI–MS (m/z 821) and IR spectroscopy (carbonyl stretch at 1733 cm−1) confirm the assigned structure. The dicyclohexylcarbodiimide (DCC) assisted acid–amine coupling reaction between 15 and [70]fulleropyrrolidine 10 resulted in the formation of the desired asymmetric triad 5, which displayed

• . 1H and 13C NMR spectra were obtained using Bruker DPX 300, Bruker DPX 400, Bruker AV(III) 400 or Bruker AV(III) 500 spectrometers. Mass spectrometry was carried out using a Bruker microTOF spectrometer and a Bruker ultraFlexIII MALDI–TOF spectrometer using trans-2-[3-(4-tert-butylphenyl)-2-methyl-2

Synthesis of nucleotide–amino acid conjugates designed for photo-CIDNP experiments by a phosphotriester approach

• Tatyana V. Abramova,
• Olga B. Morozova,
• Vladimir N. Silnikov and
• Alexandra V. Yurkovskaya

Beilstein J. Org. Chem. 2013, 9, 2898–2909, doi:10.3762/bjoc.9.326

• “Proteomics”, Russian Academy of Sciences, on an Autoflex III mass spectrometer (Bruker Daltonics, Inc.) using 2,5-dihydroxybenzoic acid as a matrix (MALDI–TOF) in positive or negative mode. Compound 22 was synthesized according to the published method [32]. Trifluoroacetamido-NH-tryptophan was obtained as

• ); MALDI–TOFMS (m/z): [M + H]+ calcd for C25H30ClN5O10P, 626.14; found, 626.05; [M + Na]+ calcd for C25H29ClN5NaO10P, 648.12; found, 648.04. General phosphorylation procedure Compound 10, 12, 15, 23, or 26 (0.2 mmol) and 1,2,4-triazole (0.08 g, 1.2 mmol) were coevaporated with Py (3 × 1 mL), dissolved in

• , H3’), 4.05–4.00 (m, 2H, OCH2CH2OP), 3.98–3.92 (m, 2H, OCH2CH2OP), 3.70 (t, J = 5.3, 2H, NHCH2CH2O), 3.68–3.64 (m, 2H, H5’5”), 3.59 (t, J = 5.3, 2H, NHCH2CH2O), 2.54–2.43 (m, 1H, H2’), 2.34–2.24 (m, 1H, H2”); MALDI–TOFMS (m/z): [M + H]+ calcd for C28H32N6O10P, 643.19; found, 643.19; [M + Na]+ calcd

Oligomeric epoxide–amine adducts based on 2-amino-N-isopropylacetamide and α-amino-ε-caprolactam: Solubility in presence of cyclodextrin and curing properties

• Julian Fischer and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 2803–2811, doi:10.3762/bjoc.9.315

• spectrometry (ESIMS) was conducted on a Bruker maXis 4G mass spectrometer and matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS) on a Bruker Dalomics Ultraflex 1 mass spectrometer. Melting points were obtained using a Büchi Melting Point B-545 apparatus at a heating

Synthesis of homo- and heteromultivalent carbohydrate-functionalized oligo(amidoamines) using novel glyco-building blocks

• Felix Wojcik,
• Sinaida Lel,
• Alexander G. O’Brien,
• Peter H. Seeberger and
• Laura Hartmann

Beilstein J. Org. Chem. 2013, 9, 2395–2403, doi:10.3762/bjoc.9.276

• -CONH2 (14): Compound 14 (30 mg, 16.2 μmol) was obtained as white hygroscopic powder after cleavage from the resin, precipitation into diethyl ether and deactylation with a yield of 81%. MALDI–TOF–MS: [M + Na]+ calcd for C75H135N13O33S3Na, 1864.83 (monoisotopic); found, 1864.63; RP-HPLC analysis 5% to 95

• deactylation compound 15 (11 mg, 5.6 μmol) was obtained as white hygroscopic powder with 28% yield. MALDI–TOF–MS: [M + H]+ calcd for C79H140N11O40S3, 1978.84 (monoisotopic); found, 1979.06; [M + Na]+ calcd for C79H139N11O40S3Na, 2000.82 (monoisotopic); found, 2000.88; [M + K]+ calcd for C79H139N11O40S3K

• deactylation in solution, the crude material was purified via preparative RP-HPLC (5 to 50% MeCN in 30 min) and freezed-dried. Compound 16 (12.6 mg, 4.2 μmol) was obtained as white hygroscopic powder with 21% yield. MALDI–TOF–MS: [M + Na]+ calcd for C124H217N23O49S6Na, 3027.34 (monoisotopic); found, 3027.71

One-pot sequential synthesis of isocyanates and urea derivatives via a microwave-assisted Staudinger–aza-Wittig reaction

• Diego Carnaroglio,
• Katia Martina,
• Giovanni Palmisano,
• Andrea Penoni,
• Claudia Domini and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2013, 9, 2378–2386, doi:10.3762/bjoc.9.274

• determined using MALDI-TOF mass spectra (Bruker Ultraflex TOF mass spectrometer). General procedures Representative procedure for alkyl isocyanate synthesis from alkyl azide: PS-PPh2 (0.477 mmol) was added to a solution of alkyl azide (0.318 mmol) in MeCN (1.5 mL). The mixture was irradiated by MW for 1.5 h

Bis(benzylamine) monomers: One-pot preparation and application in dendrimer scaffolds for removing pyrene from aqueous environments

• Olivia N. Monaco,
• Sarah C. Tomas,
• Meghan K. Kirrane and
• Amy M. Balija

Beilstein J. Org. Chem. 2013, 9, 2320–2327, doi:10.3762/bjoc.9.266

• dendrimers 11–13 (Scheme 3), which were successfully purified by size exclusion chromatography (SEC). The products were determined to be >90% pure through 1H NMR spectroscopy and their molecular weights were confirmed by MALDI–TOF. The resulting novel dendrimers contained six amino groups within the interior

• compounds 3a–g, 4a–h,6–8, and 11–13, and pyrene fluorescence spectral data. Acknowledgements We thank Tom Carberry and Marcus Weck from New York University for their help in obtaining the MALDI–TOF data and the Dean’s Office at Fordham University for its generous financial support. The Q-Tof Ultima mass

• spectrometer (University of Illinois at Urbana-Champaign) was purchased in part with a grant from the NSF, Division of Biological Infrastructure (DBI-0100085) and the Bruker MALDI–TOF/TOF UltrafleXtreme MS Spectrometer (New York University) was acquired through the support of the NSF (CHE-0958457).

Gold-catalyzed glycosidation for the synthesis of trisaccharides by applying the armed–disarmed strategy

• Abhijeet K. Kayastha and
• Srinivas Hotha

Beilstein J. Org. Chem. 2013, 9, 2147–2155, doi:10.3762/bjoc.9.252

• resolution mass spectroscopy (HRMS) was performed on ABI–MALDI–TOF using TiO2 as the solid matrix. Compound characterization data Characterization data for compound 15j [38]: [α]D25 +28.2 (CHCl3, c 1.00); 1H NMR (200.13 MHz, CDCl3) δ 1.10–2.15 (m, 10H), 2.40 (s, 1H), 3.65–4.12 (m, 6H), 4.59 (s, 2H), 4.60

• (ABq, J = 12.6 Hz, 2H), 4.71 (ABq, J = 10.6 Hz, 2H), 4.76 (s, 2H), 5.56 (d, J = 1.8 Hz, 1H), 7.13–7.42 (m, 20H); 13C NMR (50.32 MHz, CDCl3) δ 22.7, 22.7, 25.0, 37.6, 38.2, 69.3, 71.9, 72.1, 72.3, 73.3, 74.1, 75.0, 75.2, 75.2, 75.5, 80.0, 84.6, 94.0, 127.3–128.3, 138.4, 138.5, 138.5, 138.5; HRMS (MALDI

• MHz, CDCl3) δ 55.4, 65.6, 66.6, 69.0, 69.1, 69.8, 70.6, 71.3, 71.7, 71.7, 71.7, 71.7, 72.2, 72.7, 73.2, 74.2, 74.6, 74.8, 74.9, 74.9, 75.0, 79.2, 80.2, 98.1, 98.2, 98.4, 127.2–129.8, 133.1, 133.3, 133.5, 138.3, 138.3, 138.4, 138.4, 138.6, 138.6, 138.7, 165.3, 165.4, 165.5; HRMS (MALDI–TOF, m/z): [M

Straightforward synthesis of a tetrasaccharide repeating unit corresponding to the O-antigen of Escherichia coli O16

• Manas Jana and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2013, 9, 1757–1762, doi:10.3762/bjoc.9.203

• COCH3), 18.1 (CCH3); MALDI–MS: 1462.5 [M + Na]+; Anal. calcd for C76H85N3O25: C, 63.37; H, 5.95%; found: C, 63.20; H, 6.18%. p-Methoxyphenyl (β-D-galactofuranosyl)-(1→6)-(α-D-glucopyranosyl)-(1→3)-(α-L-rhamnopyranosyl)-(1→3)-2-acetamido-2-deoxy-α-D-glucopyranoside (1): Similar as described in [21]. To a