Determination of formation constants and structural characterization of cyclodextrin inclusion complexes with two phenolic isomers: carvacrol and thymol

• Miriana Kfoury,
• David Landy,
• Steven Ruellan,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2016, 12, 29–42, doi:10.3762/bjoc.12.5

• experiments were consistent. 2D NMR and molecular modeling studies revealed the geometry of the most stable inclusion complexes. Encapsulation of 1 and 2 in CDs made them more soluble in aqueous systems than their free forms and improved their radical scavenging activity. Thus, CD/1 and CD/2 inclusion

• averaging 32 scans, with a digital resolution of 0.30 Hz. 1H NMR spectra were recorded for six samples containing mixtures of β-CD and guests with guest/β-CD molar ratios ranging from 0.4 to 4. 2D NMR experiments were carried out for inclusion complexes prepared by mixing β-CD and guest in a 1:1 molar ratio

Genicunolide A, B and C: three new triterpenoids from Euphorbia geniculata

• Alia Farozi,
• Javid A. Banday and
• Shakeel A. Shah

Beilstein J. Org. Chem. 2015, 11, 2707–2712, doi:10.3762/bjoc.11.291

• 3 was further confirmed by 1H,1H, 1H,13C COSY and long range 1H,13C COSY experiments. The presence of the C-9 hydroxy group was proved by linking the carbon signal at δC 89.5 to proton signals at δ 1.01 (C-25) and 0.93 (C-26) in the 1H,13C long-range coupled spectrum. Other data for 1D and 2D NMR

Assembly of synthetic Aβ miniamyloids on polyol templates

• Sebastian Nils Fischer and
• Armin Geyer

Beilstein J. Org. Chem. 2015, 11, 2646–2653, doi:10.3762/bjoc.11.284

• (8). Template 9 and boronic acid 6 can form the monoesters 10 and 11, or the diester 12. The signal assignments were performed by homo- (DQF-COSY, TOCSY) and heteronuclear (HSQC, HMBC) 2D NMR methods. The NOESY spectrum identifies the position and the relative orientation of the aryl group of the

Recent highlights in biosynthesis research using stable isotopes

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2015, 11, 2493–2508, doi:10.3762/bjoc.11.271

• to an actively growing culture [57]. The application of 13C,13C-COSY for hypodoratoxide led to a revision of the previously proposed structure 32 [58], showing the significance of this technique in comparison to unlabeled standard 2D NMR methods. Alternatively, a completely 13C-labeled terpene can be

Bromotyrosine-derived alkaloids from the Caribbean sponge Aplysina lacunosa

• Qun Göthel,
• Thanchanok Sirirak and
• Matthias Köck

Beilstein J. Org. Chem. 2015, 11, 2334–2342, doi:10.3762/bjoc.11.254

• ), hexadellin B (10), and diacetylhexadellin B (20). NMR data of aplysinin B (3) (600 MHz, DMSO-d6) and compound 21. Cytotoxicity of the isolated compounds (IC50).a Supporting Information Supporting Information File 448: 1D, 2D NMR, and CD spectra of three new compounds. 1D NMR, mass and CD spetra of all known

Synthesis of D-fructose-derived spirocyclic 2-substituted-2-oxazoline ribosides

• Madhuri Vangala and
• Ganesh P. Shinde

Beilstein J. Org. Chem. 2015, 11, 2289–2296, doi:10.3762/bjoc.11.249

• spiro 2-substituted-2-oxazolines were stable and obtained as a single diastereomer. To assign the relative stereochemistry at the anomeric center, compounds 11a and 17a were subjected to 2D NMR analysis. In the NOESY spectra of compounds 11a and 17a, the cross peaks between C1–H, C1–H’ and CH3 groups of

Synthesis of constrained analogues of tryptophan

• Elisabetta Rossi,
• Valentina Pirovano,
• Marco Negrato,
• Giorgio Abbiati and
• Monica Dell’Acqua

Beilstein J. Org. Chem. 2015, 11, 1997–2006, doi:10.3762/bjoc.11.216

• yields, referred to the starting compounds 3/3', are reported in Scheme 2. No epimerisation reactions occurred during the hydrolytic processes as demonstrated via 2D NMR experiments (COSY, HSQC). Discussion In the Diels–Alder reaction of vinylindoles 1 with methyl 2-acetamidoacrylate (2), among tested

Stereochemistry of ring-opening/cross metathesis reactions of exo- and endo-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitriles with allyl alcohol and allyl acetate

• Piotr Wałejko,
• Michał Dąbrowski,
• Lech Szczepaniak,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 1893–1901, doi:10.3762/bjoc.11.204

• isomers was done by analysis of coupling constants 3JH,H or 3JC,H in 2D NMR (DQF and HMBC) experiments, respectively. The E/Z geometry of the double bonds were determined on the basis of 3JCH=CH constants from an 1H experiment recorded with 1H-homodecoupling or with J-resolved techniques [23]. The

• (δ) are reported in ppm downfield from TMS. The assignment of chemical shifts in solution was supported by 2D NMR experiments (DFQ, HSQC and HMBC). GC–MS was carried out on an Agilent Technologies HP 6890 N gas chromatograph with mass selective detector MSD 5973 (Agilent Technologies, USA). The

SmI₂-mediated dimerization of indolylbutenones and synthesis of the myxobacterial natural product indiacen B

• Nils Marsch,
• Peter G. Jones and
• Thomas Lindel

Beilstein J. Org. Chem. 2015, 11, 1700–1706, doi:10.3762/bjoc.11.184

• treatment of the indolylbutenone 5 with samarium diiodide in THF (formed from Sm and diiodoethane), the dimeric bisindolylcyclopentanes 6 (26%), 7 (27%) and a mixture of 8 and the open-chain dimer 9 (16%, 4:1) were isolated by semipreparative HPLC. The structures were elucidated by 2D NMR spectroscopy and

Fates of imine intermediates in radical cyclizations of N-sulfonylindoles and ene-sulfonamides

• Hanmo Zhang,
• E. Ben Hay,
• Stephen J. Geib and
• Dennis P. Curran

Beilstein J. Org. Chem. 2015, 11, 1649–1655, doi:10.3762/bjoc.11.181

• identified by 1D and 2D NMR experiments, IR and HRMS as 3-(2-formamidoethyl)-2-oxindole 25. The cyclizations of 23 and 24 gave comparable results. The corresponding formamides 26 and 27 were isolated in 42% and 54% yields, respectively. All three formamides are white solids with high melting points (>200 °C

New depsidones and isoindolinones from the mangrove endophytic fungus Meyerozyma guilliermondii (HZ-Y₂) isolated from the South China Sea

• Senhua Chen,
• Zhaoming Liu,
• Yayue Liu,
• Yongjun Lu,
• Lei He and
• Zhigang She

Beilstein J. Org. Chem. 2015, 11, 1187–1193, doi:10.3762/bjoc.11.133

• A and B (7 and 9), along with five known compounds were isolated from an endophytic fungus Meyerozyma guilliermondii, derived from the mangrove plant Kandelia obovata. Their structures were elucidated by 1D and 2D NMR spectroscopy and high resolution mass spectrometry (HREIMS). Compounds 1–6

• ). Detailed analysis of the 2D NMR spectroscopic data, the structure of 2 was established as a 3′-methylated analogue of 1. Botryorhodine G (3) was isolated as a white powder. Its molecular formula was determined as C16H14O6 by HRESIMS. The 1H and 13C NMR spectral data (Table 1) was greatly similar to those

New palladium–oxazoline complexes: Synthesis and evaluation of the optical properties and the catalytic power during the oxidation of textile dyes

• Rym Hassani,
• Mahjoub Jabli,
• Yakdhane Kacem,
• Jérôme Marrot,
• Damien Prim and
• Béchir Ben Hassine

Beilstein J. Org. Chem. 2015, 11, 1175–1186, doi:10.3762/bjoc.11.132

• distorted tetragonal coordination sphere. The two ligands coordinate to the palladium center in a trans geometry with respect to each other. All the complexes prepared in this work were characterized by IR, 1H, 13C, 2D NMR, X-ray diffraction (for 9 and 8) and UV–visible spectroscopy. The characterized bands

Are D-manno-configured Amadori products ligands of the bacterial lectin FimH?

• Tobias-Elias Gloe,
• Insa Stamer,
• Cornelia Hojnik,
• Tanja M. Wrodnigg and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2015, 11, 1096–1104, doi:10.3762/bjoc.11.123

• and 13C NMR spectra were recorded on Bruker DRX-500 and AV-600 spectrometers at 300 K and 500.13 and 125.75 MHz, respectively. Chemical shifts are reported relative to internal tetramethylsilane (δ = 0.00 ppm) or D2O (δ = 4.76 ppm). Full assignment of the peaks was achieved with the aid of 2D NMR

Synthesis of novel N-cyclopentenyl-lactams using the Aubé reaction

• Madhuri V. Shinde,
• Rohini S. Ople,
• Ekta Sangtani,
• Rajesh Gonnade and
• D. Srinivasa Reddy

Beilstein J. Org. Chem. 2015, 11, 1060–1067, doi:10.3762/bjoc.11.119

• literature and the data were compared with that reported [34]. The structure of the minor diastereomer (±)-4’ was assigned based on 2D NMR correlations. Secondly, the azido alcohol (±)-3 was subjected to a click reaction with phenylacetylene under standard conditions and the resulting two compounds, (±)-5

• and (±)-5’, were again separable by column chromatography and subsequently characterized. The NMR analysis and comparison with literature data [35] confirmed the structures of the major (±)-5 and minor isomer (±)-5’ (based on 2D NMR analysis), as shown in Scheme 2. These two experiments proved that

• , we then tested the scope of the reaction using different cyclic ketones. Thus, the reaction of the azido alcohol (±)-3 with cyclobutanone and cyclopentanone afforded the corresponding cyclopentene-substituted lactams (±)-7 and (±)-8 in good yields. The 2D NMR analysis and HMBC correlations for one of

Synthesis of a hexasaccharide partial sequence of hyaluronan for click chemistry and more

• Marina Bantzi,
• Stephan Rigol and
• Athanassios Giannis

Beilstein J. Org. Chem. 2015, 11, 604–607, doi:10.3762/bjoc.11.67

• was partially supported by the Deutsche Forschungsgemeinschaft (Transregio 67, project Z3). We thank Dr. Lothar Hennig, Universität Leipzig, for his general help and especially for recording NMR spectra and interpreting the 2D NMR spectra.

Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s

• Natalia A. Danilkina,
• Petr S. Vlasov,
• Semen M. Vodianik,
• Andrey A. Kruchinin,
• Yuri G. Vlasov and
• Irina A. Balova

Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43

• shift values in staring cinnolines 5a,b and diiodoarene 9 that allowed all 1H and 13C signals in NMR spectra of PAEs to be assigned based on 1D and 2D NMR spectra of starting compounds 5a,b, 9 and 1,4-diethynyl-2,5-bis(octyloxy)benzene (for copies of all NMR spectra see Supporting Information File 2

• NMR spectra for all compounds, copies of DEPT and 2D NMR spectra for compounds 5a,b and 7, copies of IR spectra for compounds 4a,b; 5,b; 7 and 10a,b, copies of GPC chromatograms for PAEs 10a,b. Acknowledgements This study was supported by Saint Petersburg State University (research project

Synthesis of the furo[2,3-b]chromene ring system of hyperaspindols A and B

• Danielle L. Paterson and
• David Barker

Beilstein J. Org. Chem. 2015, 11, 265–270, doi:10.3762/bjoc.11.29

• 7b showed clear differences in both the chemical shift and multiplicities in the furo[2,3-b]chromene rings (see Supporting Information File 1 for a complete table of NMR data). Extensive use of 2D NMR techniques, in particular a NOESY, allowed the complete relative stereochemistry of both 7a and 7b

A carbohydrate approach for the formal total synthesis of (−)-aspergillide C

• Pabbaraja Srihari,
• Namballa Hari Krishna,
• Ydhyam Sridhar and
• Ahmed Kamal

Beilstein J. Org. Chem. 2014, 10, 3122–3126, doi:10.3762/bjoc.10.329

• compound was also characterized by 2D NMR studies wherein significant NOESY correlations were observed for the C2 proton and the methylene protons of the carbinol moiety present on C6. Also, the NOESY correlation was absent between the C2 proton and the C6 proton (Figure 2). After the alkynylation reaction

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

• Volodymyr V. Tkachenko,
• Elena A. Muravyova,
• Sergey M. Desenko,
• Oleg V. Shishkin,
• Svetlana V. Shishkina,
• Dmytro O. Sysoiev,
• Thomas J. J. Müller and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2014, 10, 3019–3030, doi:10.3762/bjoc.10.320

• signals for the other terminal substituents. The relative stereochemistry of the stereogenic centers at positions 3 and 4 of compound 4a was established by 1D and 2D NMR spectra. Thus, a 3J coupling constant of 11.7 Hz accounts for a trans-orientation. The NOESY experiment showed only a quite weak

• , and 6''a (Figure 3). Assignment of the structure 6a was achieved with the help of 2D NMR experiments (Figure 4). COSY and NOESY spectra showed correlations between the protons of the NH and CH3 groups in the tetrahydropyridine ring which should be absent in case of structure 6''a. Neither scalar nor

• stereogenic centers at positions 4 and 12 of compound 6a was first established by analysis of the 1D and 2D NMR spectra. Thus, a 3J coupling constant of 1.9 Hz corresponds with a cis-orientation and the NOESY experiment additionally supports the proximity of this pair of protons. The structure of compound 6a

Trogopterins A–C: Three new neolignans from feces of Trogopterus xanthipes

• Soyoon Baek,
• Xuikui Xia,
• Byung Sun Min,
• Chanil Park and
• Sang Hee Shim

Beilstein J. Org. Chem. 2014, 10, 2955–2962, doi:10.3762/bjoc.10.313

• neolignans 1–3, a norlignan 4, and three diterpenoids 5–7, were isolated from the feces of Trogopterus xanthipes. Structures of these compounds were identified by 1D and 2D NMR as well as MS. The absolute configurations of compounds 1, 2, and 4 were determined by comparing CD spectra and optical rotations

• with a Jasco P1000 digital polarimeter. UV spectra were recorded by a Hewlett Packard 8453 UV–vis spectrometer. CD spectra were obtained with a Jasco J-715 circular dichroism spectrophotometer. 1D and 2D NMR were performed on a VNS 600 MHz spectrometer operating at 600 MHz for protons and 150 MHz for

Stereoselective synthesis of perillaldehyde-based chiral β-amino acid derivatives through conjugate addition of lithium amides

• Zsolt Szakonyi,
• Reijo Sillanpää and
• Ferenc Fülöp

Beilstein J. Org. Chem. 2014, 10, 2738–2742, doi:10.3762/bjoc.10.289

• determined by 2D NMR techniques. Remarkable nOe correlations were observed between C2-H and C9-Me (10A and 10D), between C1-H and C8-H (10A), and a weak effect was found between C1-H and C8-H (10B) (see Figure 1 for numbering). Amino esters 7A–D were transformed to the appropriate amino acids 10A–D in three

Aspergiloid I, an unprecedented spirolactone norditerpenoid from the plant-derived endophytic fungus Aspergillus sp. YXf3

• Zhi Kai Guo,
• Rong Wang,
• Wei Huang,
• Xiao Nian Li,
• Rong Jiang,
• Ren Xiang Tan and
• Hui Ming Ge

Beilstein J. Org. Chem. 2014, 10, 2677–2682, doi:10.3762/bjoc.10.282

• , 40.0, 88.6, 126.6, 170.9, 171.6). These data show that 1 has two double bonds and one carbonyl which require three degrees of unsaturation, thus, 1 must also contain three rings. The gross structure of 1 was initially deduced by comprehensive analysis of its 1D and 2D NMR data. The 13C NMR and HSQC

• Supporting Information File 462: 1D, 2D NMR spectra, HRMS–ESI, and the X-ray crystallographic structure of 1. Acknowledgements We thank Dr. Jeffrey Rudolf (The Scripps Resarch Institute, Jupiter, FL) for editing this manuscript. This work was cofinanced by National Natural Science Foundation of China

Selenium halide-induced bridge formation in [2.2]paracyclophanes

• Laura G. Sarbu,
• Henning Hopf,
• Peter G. Jones and
• Lucian M. Birsa

Beilstein J. Org. Chem. 2014, 10, 2550–2555, doi:10.3762/bjoc.10.266

• in situ prepared SeCl2 [28], in chloroform at 0 °C, a mixture of unexpected addition products has been obtained (Scheme 1). After separation by column chromatography, we assigned the structures of isomeric cyclic dienes 2 and 3 and the tetrachloro derivative 4 on the basis of 2D NMR studies and mass

• [28], in chloroform at 0 °C, provided a mixture of isomeric cyclic dienes 5 and 6, and the tetrabromo derivative 7 (Scheme 1, Table 1, entry 3) in 76% yield. Again, the structures of these compounds, as well as the configuration of diene 5, have been established on the basis of 2D NMR studies, mass

Regio- and stereoselective synthesis of new diaminocyclopentanols

• Evgeni A. Larin,
• Valeri S. Kochubei and
• Yuri M. Atroshchenko

Beilstein J. Org. Chem. 2014, 10, 2513–2520, doi:10.3762/bjoc.10.262

• aminocyclopentanols 8c and 8d (Supporting Information File 1). In every experiment, 1,2-trans-2,3-cis-aminocyclopentanols, arising from opening of epoxide 3a at C1, were the only regioisomers isolated. The stereo- and regiochemistry of 8a and 8d were assigned by 2D NMR (HSQC-DEPT, 1H,1H COSY and NOESY experiments

• absence of the C(2)H-C(5)H correlation in the NOESY spectrum support the stereochemistry of 8a. The same relative configuration of 8d was assigned from 2D NMR analysis, and the stereochemistry of 8b and 8c was additionally confirmed by the comparison of 3J coupling constants of the resonances

• stereochemistry of the major regioisomers 9a–d was deduced from the analysis of 1H NMR and 2D NMR data as described for 8a–d. Assignments of CH proton resonances of 10a–d were established by 1H,13C HMBC and HSQC-DEPT experiments, and connectivity was established by the analysis of 1H,1H COSY spectra. The

Oxidative phenylamination of 5-substituted 1-hydroxynaphthalenes to N-phenyl-1,4-naphthoquinone monoimines by air and light “on water”

• Julio Benites,
• Juan Meléndez,
• Cynthia Estela,
• David Ríos,
• Luis Espinoza,
• Iván Brito and
• Jaime A. Valderrama

Beilstein J. Org. Chem. 2014, 10, 2448–2452, doi:10.3762/bjoc.10.255

• NMR, 2D NMR) and high resolution mass spectrometry (HRMS). The position of the nitrogen substituent in these aminoquinones was determined by means of HMBC experiments. Encouraged by these results, the preparation of aminojuglones 4a and 4b was attempted by employing the hypothetical one pot procedure

• )naphthalene-1(4H)-one (6, 98% yield). Under similar conditions, but using green LEDs light radiation, compound 6 was isolated in 80% yield. The structure of 6 was established by means of 1D and 2D NMR and by X-ray crystallographic studies (Figure 2 and Table S1 in Supporting Information File 1). This