[²H₂₆]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2841–2845, doi:10.3762/bjoc.9.319

• shifts [10], stereospecific conversions along multistep biosynthetic pathways [11], hydride abstractions in oxidation steps [12], or deprotonations [13] are to be followed. Its incorporation is best observed by GC–MS, and if fragmentation mechanisms are known [14], the site of incorporation can be

• ], followed by extraction with dichloromethane and GC–MS analysis of headspace extracts. While 2-MIB (1), caryolan-1-ol (2) and 1-epi-cubenol (3) were all produced during growth on full medium (65.GYM), consistent with previous results using other full media [26], only for 3 similar levels of production were

• –24 h. The absorbed volatiles were eluted with analytically pure dichloromethane (40–50 μL) and the extract (1 μL) was immediately analyzed by GC–MS. The rest was stored at −80 °C for future reference. GC–MS. GC–MS analyses were carried out on an Agilent 7890A connected with an Agilent 5975C inert

Halogenated volatiles from the fungus Geniculosporium and the actinomycete Streptomyces chartreusis

• Tao Wang,
• Patrick Rabe,
• Christian A. Citron and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 2767–2777, doi:10.3762/bjoc.9.311

• brominated or even iodinated volatiles are even more rare. Surprisingly, headspace extracts from Streptomyces chartreusis contained methyl 2-iodobenzoate, a new natural product that adds to the small family of iodinated natural products. Keywords: constitutional isomerism; GC-MS; natural products

• Geniculosporium sp. 9910 were trapped on charcoal filters by using a closed-loop stripping apparatus (CLSA) [20]. After one day of collection a solvent extract of the trapped material was analysed by GC–MS. The analytical process was performed three times to demonstrate reproducibility of the results, and a

• benzyltrimethylammonium tetrachloroiodate in moderate yield (34%) [22]. All six compounds were subjected to GC–MS analysis using the same type of GC column as for the headspace extract from Geniculosporium (HP5-MS) and their retention indices together with the NMR spectroscopic data are summarised in Table 2. Mass

Reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithiethane with N-vinyl compounds

• Viacheslav A. Petrov and
• Will Marshall

Beilstein J. Org. Chem. 2013, 9, 2615–2619, doi:10.3762/bjoc.9.295

• internal standard. CDCl3 was used as a lock solvent. GC and GC–MS analyses were carried out on a HP-6890 instrument by using an HP FFAP capillary column and either TCD (GC) or mass-selective (GC–MS) detectors, respectively. Dry DMF (water <100 ppm), vinylamines 2a–e and 4 (Aldrich), sulfur (Alfa Aesar

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

• , respectively) at 25 °C; chemical shifts were calibrated to the residual proton and carbon resonances of the solvents: CDCl3 (δH = 7.26, δC = 77.16) or CD3OD (δH = 3.31, δC = 49.00). GC–MS analyses were performed in a GC Agilent 6890 (Agilent Technologies, USA) that was fitted with a mass detector Agilent

Crystal design using multipolar electrostatic interactions: A concept study for organic electronics

• Peer Kirsch,
• Qiong Tong and
• Harald Untenecker

Beilstein J. Org. Chem. 2013, 9, 2367–2373, doi:10.3762/bjoc.9.272

• processability. Experimental General remarks: Reagents and solvents were obtained commercially and used as supplied. 1H and 19F NMR spectra were collected using a Bruker Avance 400 spectrometer. 1H NMR chemical shifts were referenced to the solvent signal. GC–MS experiments were performed on an Agilent 7890A

Elucidation of the regio- and chemoselectivity of enzymatic allylic oxidations with Pleurotus sapidus – conversion of selected spirocyclic terpenoids and computational analysis

• Verena Weidmann,
• Mathias Schaffrath,
• Holger Zorn,
• Julia Rehbein and
• Wolfgang Maison

Beilstein J. Org. Chem. 2013, 9, 2233–2241, doi:10.3762/bjoc.9.262

• hydrogen abstraction in position 2, spiroether 7 was selectively converted to the spirolactone 14. The alternative oxidation product 15 was not found by GC–MS. The regioisomeric spiroether 8 offers only one plausible path for allylic oxidation in position 3. However, this spiroether was not converted at

A concise enantioselective synthesis of the guaiane sesquiterpene (−)-oxyphyllol

• Martin Zahel and
• Peter Metz

Beilstein J. Org. Chem. 2013, 9, 2028–2032, doi:10.3762/bjoc.9.239

• (triplet), q quartet), br (broad). Coupling constants (J) are quoted to the nearest 0.1 Hz. Mass spectra were recorded with an Agilent 5973N detector coupled with an Agilent 6890N GC (GC–MS, 70 eV). HRMS spectra were recorded on a Finnigan MAT 95 (EI, 70 eV). Optical rotations were measured on a Perkin

• , 977 cm−1; GC–MS: m/z = 296 [M]+; anal. calcd for C15H20O4S: C 60.79, H 6.80; found: C 60.88, H 6.92. Alcohol 3: Epoxide 4 (100.0 mg, 454 μmol) and cobalt(II) acetylacetonate (23.3 mg, 91 μmol) were dissolved in THF (5 mL), and the solution was cooled to 0 °C. Oxygen was bubbled through the solution

• : 3446, 2957, 2930, 2874, 1708, 1130, 852 cm−1; GC–MS: m/z = 238 [M]+; HRMS (EI) m/z: [M]+ calcd for C14H22O3, 238.1569; found, 238.1564. Allyl ether 11: Methyltriphenylphosphonium bromide (131.5 mg, 368 μmol) was suspended in THF (1.5 mL), and a solution of sodium hexamethyldisilazide in THF (2.0 M, 172

Damage of polyesters by the atmospheric free radical oxidant NO₃^•: a product study involving model systems

• Catrin Goeschen and
• Uta Wille

Beilstein J. Org. Chem. 2013, 9, 1907–1916, doi:10.3762/bjoc.9.225

• )] in deuterated DMSO. If necessary the assignment of the chemical shifts was confirmed by utilising 2D NMR techniques. GC–MS (EI, 70 eV) analysis was run on an Agilent 7890A GC/5975C MSD, column from SUPELCO 30 m, 0.32 mm ID, 0.25 μm film thickness fused silica capillary column, using the temperature

Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping

• Skrollan Stockinger and
• Oliver Trapp

Beilstein J. Org. Chem. 2013, 9, 1837–1842, doi:10.3762/bjoc.9.214

• evaporation the reaction mixture was dissolved in pentane and washed with water. The diluted pentane solution was analyzed by GC–MS. For the ocRGC analysis separate DCM solutions of anthracene or anthracene derivative and benzenediazonium-2-carboxylate were prepared, both containing 1 mg per mL. The injection

• -order reactions. Experimental Benzenediazonium-2-carboxylate was synthesized according to a procedure described in [33][34]. Anthracene, 9-bromoanthracene, 9-anthracenecarboxaldehyde and 9-anthracenemethanol were purchased from Aldrich Chemical, Acros or ABCR and used without further purification. As GC

• –MS a Trace GC Ultra combined with an ISQ Single Quadrupole mass spectrometer, both from Thermo Scientific, were used. For cryofocusing a Cryogenic CO2 Cold Trap System by SGE Analytical Science was installed, according to the experimental setup outlined in Figure 2. For cryofocusing CO2 was used as a

Activation of cryptic metabolite production through gene disruption: Dimethyl furan-2,4-dicarboxylate produced by Streptomyces sahachiroi

• Dinesh Simkhada,
• Huitu Zhang,
• Shogo Mori,
• Howard Williams and
• Coran M. H. Watanabe

Beilstein J. Org. Chem. 2013, 9, 1768–1773, doi:10.3762/bjoc.9.205

• characterization of the major metabolite was carried out using LC–MS analysis and 1D and 2D cryoprobe NMR spectroscopy (data provided in Supporting Information File 1). The molecular formula was established as C8H8O5 based upon a molecular ion peak observed by LC–APCIMS at m/z 185.0453 [M + H]+ and GC–MS. The GC

• –MS fragmentation of the compound matched that provided in the Ultra GC–DSQ (ThermoElectron, Waltham, MA) GC–MS database. The structure of the compound was determined by NMR analysis in CDCl3 (Table 1). The presence of two O-CH3 groups at C-2’ (δc 51.99, δH 3.94) and C-2” (δc 52.31, δH 3.88) and

• flow rate of 0.75 mL/min in 254 nm UV. The same program was used for LC–APCI analysis. For GC–MS analysis, the sample was diluted 1:10 in DCM and was performed on an Ultra GC/DSQ (ThermoElectron, Waltham, MA). A Rxi-5ms gas chromatographic column was utilized with dimensions of 60 m length, 0.25 mm i.d

Gold-catalyzed intermolecular coupling of sulfonylacetylene with allyl ethers: [3,3]- and [1,3]-rearrangements

• Jungho Jun,
• Hyu-Suk Yeom,
• Jun-Hyun An and
• Seunghoon Shin

Beilstein J. Org. Chem. 2013, 9, 1724–1729, doi:10.3762/bjoc.9.198

• the presence of the Au-catalyst, no cross-over product was observed by GC–MS and NMR spectrometry, indicating the [3,3]- and [1,3]-rearrangement occurred intramolecularly (Scheme 2, reaction 2). This was further confirmed by the cross-over experiment employing 2i and 2m, two α-substituted allyl ethers

The preparation of several 1,2,3,4,5-functionalized cyclopentane derivatives

• André S. Kelch,
• Peter G. Jones,
• Ina Dix and
• Henning Hopf

Beilstein J. Org. Chem. 2013, 9, 1705–1712, doi:10.3762/bjoc.9.195

• derivatives of 16, it should also be mentioned that attempts to prepare the corresponding pentachloride (by treatment with either SOCl2 or PCl3) and pentaiodide (red P/iodine) also failed. In all these experiments complex product mixtures resulted, the GC–MS analysis of which demonstrated that only partially

•  5). Finally, the hydrogenation of 28 over Pd/C in methanol furnished a mixture of the saturated pentaesters 26 and 27 (ratio 4:1, capillary GC–MS-analysis) in practically quantitative yield (98%). Although we were unable to separate the two components quantitatively by column chromatography on

Bromination of hydrocarbons with CBr₄, initiated by light-emitting diode irradiation

• Yuta Nishina,
• Bunsho Ohtani and
• Kotaro Kikushima

Beilstein J. Org. Chem. 2013, 9, 1663–1667, doi:10.3762/bjoc.9.190

• species for the bromination. The generation of CHBr3 was confirmed by NMR spectroscopy and GC–MS spectrometry analysis, indicating that the present bromination involves the homolytic cleavage of a C–Br bond in CBr4 followed by radical abstraction of a hydrogen atom from a hydrocarbon. Keywords

• (0.50 mmol) dissolved in cyclohexane (0.10 mL) and CDCl3 (0.40 mL) (Figure 2b). Additionally, the generation of CHBr3 in the present bromination was confirmed by 1H NMR spectroscopy and GC–MS spectrometry. These results support the reaction pathway described above, although the chemical species after

Mechanistic studies on the CAN-mediated intramolecular cyclization of δ-aryl-β-dicarbonyl compounds

• Brian M. Casey,
• Dhandapani V. Sadasivam and
• Robert A. Flowers II

Beilstein J. Org. Chem. 2013, 9, 1472–1479, doi:10.3762/bjoc.9.167

• system from Teledyne Isco, Inc. All new compounds were characterized by 1H NMR, 13C NMR, GC–MS, IR, and LC–HRMS. Known compounds were characterized by 1H NMR, 13C NMR and GC–MS. 1H NMR and 13C NMR spectra were recorded on a Bruker 500 MHz spectrometer. Mass spectra were obtained by using a HP 5890 series

• GC–MS instrument. A Satellite FTIR from Thermo-Mattson was used to obtain IR spectra. LC–HRMS data were recorded at the Mass Spectrometry Facility at Notre Dame University. General procedure for the synthesis of δ-aryl-β-dicarbonyl compounds 1a–j. Sodium hydride (11 mmol) was suspended in 25 mL of

Isolation and X-ray characterization of palladium–N complexes in the guanylation of aromatic amines. Mechanistic implications

• Abdessamad Grirrane,
• Hermenegildo Garcia and
• Eleuterio Álvarez

Beilstein J. Org. Chem. 2013, 9, 1455–1462, doi:10.3762/bjoc.9.165

• S21 and S22 for 5a, Figures S24 and S25 for 5b, our recent published work for 5c [20] and experimental section in Supporting Information File 1). ESIMS and GC–MS of solutions obtained respectively after dissolving guanidines 5a and 5b in CH2Cl2/MeOH (1:1) and CH2Cl2 shows a single positive MS peak at

• and GC–MS spectra for new compounds. Supporting Information File 380: X-Ray structure analysis data for 4a (CCDC-931786, 4b (CCDC-931787), 4c (CCDC-931788) and 5a (CCDC-931789) are given. These data can also be obtained free of charge from The Cambridge Crystallographic Data Centre via http

Palladium-catalyzed synthesis of N-arylated carbazoles using anilines and cyclic diaryliodonium salts

• Stefan Riedmüller and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2013, 9, 1202–1209, doi:10.3762/bjoc.9.136

• equal or better in efficiency and yield. Changing Pd2(dba)3 to Pd(OAc)2 had no significant impact on product yields (Table 1, entry 12). Further increase of the catalyst ratio from 5 to 10 mol % had little effect (Table 1, entry 15). Next, we decided to analyze the byproducts of this reaction by GC–MS

• GC–MS analysis, we could detect 2-iodobiphenyl, 2,2'-diiodobiphenyl, 2-(2,5-dimethylphenyl)-2'-iodobiphenyl, and 2'-iodo-N-phenylbiphenyl-2-amine in the absence of any produced 3a. Contrary to that observation, when we conducted an analogous experiment without aniline, we observed no decomposition or

Interplay of ortho- with spiro-cyclisation during iminyl radical closures onto arenes and heteroarenes

• Roy T. McBurney and
• John C. Walton

Beilstein J. Org. Chem. 2013, 9, 1083–1092, doi:10.3762/bjoc.9.120

• communicated previously, 3-substituted phenanthridines 10a–f were isolated in good to quantitative yields (52–99%, Scheme 1) irrespective of the nature of the 4-substituent [26]. No spiro-products were detected even by GC–MS analyses of reaction mixtures. Byproducts included traces of imines ArC(R2)=NH (ImH

Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria

• Nelson L. Brock,
• Christian A. Citron,
• Claudia Zell,
• Martine Berger,
• Irene Wagner-Döbler,
• Jörn Petersen,
• Thorsten Brinkhoff,
• Meinhard Simon and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2013, 9, 942–950, doi:10.3762/bjoc.9.108

• ) were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC–MS. Feeding experiments with [2H6]DMSP resulted in the

• by solid-phase microextraction (SPME) and by CLSA. The obtained headspace extracts were subsequently analyzed by GC–MS, leading to the identification of the volatiles dimethyl disulfide (1), dimethyl trisulfide (2), S-methyl methanethiosulfonate (3), dimethyl telluride (4), dimethyl telluryl sulfide

• GC–MS. No incorporation of the 34S-labeling from sulfate or thiosulfate into the MeSH-derived volatiles was observed, pointing strongly away from a significant involvement of sulfate reduction in the biosynthesis of MeSH. Instead, feeding of [methyl-2H3]methionine led to an effective incorporation of

4-Pyridylnitrene and 2-pyrazinylcarbene

• Curt Wentrup,
• Ales Reisinger and
• David Kvaskoff

Beilstein J. Org. Chem. 2013, 9, 754–760, doi:10.3762/bjoc.9.85

• ’-Azopyridine (25) (54% yield; red solid, mp 107–108 °C) was identified by comparison with a sample prepared according to den Hertog et al. (mp 107.5 °C) [22]. Traces of unreacted azide 18 and 2- and 3-cyanopyrroles 16 and 17were detected by GC–MS and IR spectroscopy. “Violent pyrolysis” was achieved by holding

3-Pyridylnitrene, 2- and 4-pyrimidinylcarbenes, 3-quinolylnitrenes, and 4-quinazolinylcarbenes. Interconversion, ring expansion to diazacycloheptatetraenes, ring opening to nitrile ylides, and ring contraction to cyanopyrroles and cyanoindoles

• Curt Wentrup,
• Nguyen Mong Lan,
• Adelheid Lukosch,
• Pawel Bednarek and
• David Kvaskoff

Beilstein J. Org. Chem. 2013, 9, 743–753, doi:10.3762/bjoc.9.84

• g) was distilled into the FVT apparatus from a sample flask held at −30 °C and thermolysed at 370–500 °C/10−3–10−4 mbar in the course of 2 h. The pyrolysate was examined by GC/MS and 1H NMR spectroscopy. The 2- and 3-cyanopyrroles 7 and 8 were separated by flash chromatography on silica gel 60

• remained unreacted); 400 °C: 1.63:1 (36% 3-azidopyridine remained unreacted); 500 °C: 1.48:1 (6% 3-azidopyridine remained unreacted). GC/MS retention times and molecular masses: 2-cyanopyrrole 3.60 min (m/z 92); 3-cyanpyrrole 5.45 min (m/z 92); 3-azidopyridine 2.19 min (m/z 120); 1H NMR (CDCl3) 2

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

• EtOAc. The combined organic layers were dried over Na2SO4 and purified by column chromatography (DCM/MeOH 99:1) to obtain 7.56 g (61%) of the desired product as a colorless oil. Rf 0.42 (DCM/MeOH 9:1); HRMS (GC–MS): [M + H]+ calcd for C4H10ONS, 120.04776; found, 120.04730; 1H NMR (400 MHz, CDCl3-d1

• :5) to obtain 200 mg (37%) of 2 as a slightly yellow oil. Rf 0.5 (DCM/MeOH 9:1); HRMS (GC–MS): [M + H]+ calcd for C8H122H3O4, 178.11532; found, 178.11512; 1H NMR (400 MHz, CDCl3-d1) 1.46 (s, 9H), 3.36 (s, 1H); 13C NMR (101 MHz, CDCl3-d1) 21.1, 28.2, 47.0 ,82.7, 169.6, 176.6. Synthesis of tert-butyl 3

Kinetics and mechanism of the anilinolysis of aryl phenyl isothiocyanophosphates in acetonitrile

• Hasi Rani Barai and
• Hai Whang Lee

Beilstein J. Org. Chem. 2013, 9, 615–620, doi:10.3762/bjoc.9.68

• , 1H, aliphatic), 7.01–7.43 (m, 15H, aromatic); 13C NMR (100 MHz, MeCN-d3) δ 118.59–131.20 (m, 18C; aromatic); 31P NMR (162 MHz, MeCN-d3) δ 3.62 (d, J = 8.6 Hz, 1P, P=O); GC–MS (EI, m/z): 325 (M+). Brönsted plots with X [log kH versus pKa(X)] of the reactions of Y-aryl phenyl isothiocyanophosphates

Intramolecular carbolithiation cascades as a route to a highly strained carbocyclic framework: competition between 5-exo-trig ring closure and proton transfer

• William F. Bailey and
• Justin D. Fair

Beilstein J. Org. Chem. 2013, 9, 537–543, doi:10.3762/bjoc.9.59

• % isolated yield. Quenching with MeOD afforded an authentic sample of 4 deuterated at the C(2) position (2H NMR: δ 5.84–5.75 (m, 1D)); the lack of a molecular ion in the GC–MS of triene 4 precluded accurate determination of the deuterium content. Addition at –78 °C of dry, oxygen-free N,N,N’,N

• GC and by GC–MS affording baseline separation of the three products (4–6), illustrated in Scheme 4, which accounted for essentially the total material balance. The structures of the bicyclic products, 5 and 6, were established as detailed in the Experimental Section (see Supporting Information File 1

• for details) by NMR and GC–MS: an authentic sample of 5 was prepared as illustrated below and 6 is a known compound [20]. It is noteworthy that no 1-methylstellane was detected as a product from any of the reactions. Stirring a reaction mixture for 1 h at room temperature demonstrated that the first

Easy and direct conversion of tosylates and mesylates into nitroalkanes

• Alessandro Palmieri,
• Serena Gabrielli and
• Roberto Ballini

Beilstein J. Org. Chem. 2013, 9, 533–536, doi:10.3762/bjoc.9.58

• methodology [42]. 1H NMR was recorded at 400 MHz on a Varian Mercury Plus 400. 13C NMR was recorded at 100 MHz. Microanalyses were performed with a CHNS-O analyser Model EA 1108 from Fisons Instruments. Mass spectra were performed with a GC–MS system Agilent Technologies 6850 II/5973 Inert by means of the EI

• –n. Supporting Information All synthesized products were characterized by IR, NMR, GC–MS and elementary analysis. The data is reported in Supporting Information File 1, while copies of 1H and 13C NMR spectra are attached as Supporting Information File 2. Supporting Information File 365

Efficient Cu-catalyzed base-free C–S coupling under conventional and microwave heating. A simple access to S-heterocycles and sulfides

• Silvia M. Soria-Castro and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2013, 9, 467–475, doi:10.3762/bjoc.9.50

• amounts of the substituted thioacetate derivative S-(2-acetoamidophenyl)thioacetate (15) and N-(2-mercaptophenyl)acetamide (16) or S-(2-aminophenyl)thioacetate (17) without cyclization, as detected by GC–MS spectrometry (Scheme 6). In order to accelerate the ring-closure reaction, a mixture of 13 and 1 in