An economical and safe procedure to synthesize 2-hydroxy-4-pentynoic acid: A precursor towards ‘clickable’ biodegradable polylactide

• Quanxuan Zhang,
• Hong Ren and
• Gregory L. Baker

Beilstein J. Org. Chem. 2014, 10, 1365–1371, doi:10.3762/bjoc.10.139

• change of KI-starch test paper), which destroy product 1 during concentration and drying under vacuum. And neither addition of urea (reacting with HNO2 to release N2, CO2 and H2O) nor passing of crude product 1 through a short silica gel column can stop its decomposition. So three reductants were

• acid 6 at 0 °C followed by the addition of another 3 equiv of NaNO2 in water (40%). The resulting mixture was stirred for 40 h at room temperature, and urea in diluted HCl (1 M) was added dropwise until the mixture did not make potassium iodide starch test paper blue or purple. The resulting product 1

• was extracted with ether using a continuous extraction apparatus. Solid Na2S2O5 was added to ether layer and the resulting mixture was stirred until it did not turn potassium iodide starch test paper to purple. After removal of Na2S2O5 via filtration, the ether layer was concentrated, dried and

Carbenoid-mediated nucleophilic “hydrolysis” of 2-(dichloromethylidene)-1,1,3,3-tetramethylindane with DMSO participation, affording access to one-sidedly overcrowded ketone and bromoalkene descendants^§

• Rudolf Knorr,
• Thomas Menke,
• Johannes Freudenreich and
• Claudio Pires

Beilstein J. Org. Chem. 2014, 10, 307–315, doi:10.3762/bjoc.10.28

• NaOCl solution in an amount that sufficed for showing a positive potassium iodide/starch test for 30 min, at which time this residual NaOCl was forthwith destroyed by solid NaHSO3 that had to be added until the KI/starch test became negative. (KMnO4 in place of NaOCl was found to decompose 17.) The

The myxocoumarins A and B from Stigmatella aurantiaca strain MYX-030

• Tobias A. M. Gulder,
• Snežana Neff,
• Traugott Schüz,
• Tammo Winkler,
• René Gees and
• Bettina Böhlendorf

Beilstein J. Org. Chem. 2013, 9, 2579–2585, doi:10.3762/bjoc.9.293

• . aurantiaca MYX-030, inoculated directly from a single culture of an agar plate, was incubated by shaking (150 rpm) at 30 °C for 7 days in a 500 mL shake flask without baffle containing 80 mL of medium MIX-5 (composition: 2 g glucose, 5 g potato starch, 2 g peptone, 0.5 g MgSO4, 0.5 g CaCl2, 10 g HEPES for 1

• L H2O, pH 7.4). For production of myxocoumarins, 3 × 200 mL production cultures in 500 mL flasks without baffle were inoculated with 20 mL of the preculture. Production was carried out by shaking (150 rpm) at 30 °C for 10 days in MIX-1 media (composition: 5 g casitone, 2 g starch, 2 g MgSO4, 0.5 g

Quantification of N-acetylcysteamine activated methylmalonate incorporation into polyketide biosynthesis

• Stephan Klopries,
• Uschi Sundermann and
• Frank Schulz

Beilstein J. Org. Chem. 2013, 9, 664–674, doi:10.3762/bjoc.9.75

• : 5 g glucose, 50 g Glucidex IT29 (Roquette), 83.83 g NaHCO3, and 186 mg Na2CO3 were dissolved in 1 L of Millipore water to obtain 1 M carbonate feeding buffer at pH = 8. Rapamycin: 30 g starch (corn), 1 g yeast, 30 g Toasted Nutrisoy, 19 g Dextrin, 10 g NaCl, 83.83 g NaHCO3, and 186 mg Na2CO3 were

Cyclodextrin-based nanosponges as drug carriers

• Francesco Trotta,
• Marco Zanetti and
• Roberta Cavalli

Beilstein J. Org. Chem. 2012, 8, 2091–2099, doi:10.3762/bjoc.8.235

• and are synthesised by enzymatic action on hydrolysed starch. The main common native cyclodextrins are α, β and γ, which comprise six, seven and eight glucopyranose units, respectively. They have a characteristic toroidal shape, which forms a well-defined truncated cone-shaped lipophilic cavity

Superstructures with cyclodextrins: Chemistry and applications

• Helmut Ritter

Beilstein J. Org. Chem. 2012, 8, 1303–1304, doi:10.3762/bjoc.8.148

• ), 7 (β) and 8 (γ) 1,4-glycosidically linked α-D-glucose units. Production of these compounds is accomplished by enzymatic degradation of starch using CD-glycosyl transferase. Since their discovery more than 100 years ago, a significant development in CD research has taken place. Right after their

Unprecedented deoxygenation at C-7 of the ansamitocin core during mutasynthetic biotransformations

• Tobias Knobloch,
• Gerald Dräger,
• Wera Collisi,
• Florenz Sasse and
• Andreas Kirschning

Beilstein J. Org. Chem. 2012, 8, 861–869, doi:10.3762/bjoc.8.96

• concentration in the main culture corresponds to 5/6 of the values given for this medium due to dilution) – 60 g/L dextrin from maize starch (Fluka), 30 g/L D(+)-maltose∙H2O (Fluka), 5.25 g/L cottonseed flour (Proflo), 5 g/L CaCO3, 4.5 g/L yeast extract (Bacto), 300 mg/L K2HPO4 (Fluka, TraceSelect), 2 mg/L

Cyanoethylation of the glucans dextran and pullulan: Substitution pattern and formation of nanostructures and entrapment of magnetic nanoparticles

• Kathrin Fiege,
• Heinrich Lünsdorf,
• Sevil Atarijabarzadeh and
• Petra Mischnick

Beilstein J. Org. Chem. 2012, 8, 551–566, doi:10.3762/bjoc.8.63

• spectroscopy (PEELS). Keywords: cyanoethyldextran; cyanoethylpullulan; ferromagnetic nanoparticles; glycan nanostructures; substitution pattern; Introduction Cyanoethylation has been widely applied to polysaccharides, e.g., to cellulose [1], inulin [2], and starch [3]. Onda reported on cyanoethylation of

• structural characterization of the material. Cyanoethylation is established for polysaccharides, but the substituent pattern has only been studied for cyanoethylamylose and starch [3]. In most cases, the products have only been roughly characterized by NMR and IR spectroscopy or by elementary analysis [1][2

• ]. Verraest described the substituent distribution in O-cyanoethylinulin by HPLC analysis and 13C NMR spectroscopy [7]. The structure and the solution properties of cyanoethylcellulose were investigated by FT–IR and 13C NMR spectroscopy, as well as by light scattering [21][22]. Cellulose and starch

Air-stable, recyclable, and time-efficient diphenylphosphinite cellulose-supported palladium nanoparticles as a catalyst for Suzuki–Miyaura reactions

• Qingwei Du and
• Yiqun Li

Beilstein J. Org. Chem. 2011, 7, 378–385, doi:10.3762/bjoc.7.48

• ligands [23][24][25] or palladium(0) nanoparticles on various solid supports [26][27][28][29][30][31] (polystyrene [26], silica [27], cellulose [28], corn starch [29], polymethyl methacrylate [30] and others [31]). In addition, cellulose as efficient support for Pd nanoparticles in other cross-coupling

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

• Daniel Crespy and
• Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

• variety of polymers, e.g., with epoxy, polyurethane (Figure 7), and polyurea, or based on synthetic polyamines, polythiourea, crosslinked starch, dextran or polyethylene imine [116]. Therefore, the functionality can be directly implemented in the capsules by using an excess of one of the monomers, or by

• synthesis to carry out a polymerase chain reaction (PCR) in crosslinked starch nanocapsules [121]. The permeability of the shell was also evaluated by fluorescence spectroscopy. The combination of cleavable polyurethane [109] with the interfacial polyaddition described above [116] afforded polymer shells

Functionalized polymers: synthesis and properties

• Helmut Ritter

Beilstein J. Org. Chem. 2010, 6, No. 55, doi:10.3762/bjoc.6.55

• , naturally occurring polymers as cellulose or polyisoprene were simply modified, for example by esterification or cross-linking to obtain the desired properties. Hermann Staudinger, for instance, chemically modified starch to prove the existence of high molecular weight substances. Nowadays, the development