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• Structures of reaction products between sulfolane cis - or trans -amino alcohols and aromatic aldehydes were defined • New sulfolane hydroxyimines were synthesized and characterized by 1D/2D NMR and X-ray techniques • cis -Imines in the CDCl 3 solution exist in equilibrium with two cyclic tautomers, while the corresponding trans -imines are not able to similar tautomeric transformations. The introduction of electron withdrawing substituents in the benzene ring, contributes to the increase of the content of cyclic (1,3-oxazolidine) forms • It was shown that in DMSO- d 6 solution equilibrium hydroxyimine-oxazolidine shifted towards hydroxyimine in time • Pharmacological profile of the products was evaluated in silico using ADMETlab 2.0 and SwissADME software Cyclic sulfones and their derivatives have vast applications in biological, pharmaceutical, medicinal and in many other fields. Herein, we report synthesis of ten new hydroxyimines bearing sulfolane moiety by reaction of cis - and trans -amino alcohols with aromatic aldehydes. An extensive spectroscopic characterization of the products, using 1D and 2D NMR techniques (1H, 13C, NOE, NOESY, COSY, HSQC, HMBC) showed ring-chain tautomerism in deuterochloroform solution for cis -hydroxyimines. The content of the cyclic (1,3-oxazolidine) form increases with increasing electron-withdrawing strength of the substituent in the para position of the benzene ring of the imine. The structure of cis -(3 S ,4 R)-3-hydroxy-4-((E)-(2-hydroxybenzylidene)amino)tetrahydrothiophene 1,1-dioxide was confirmed using XRD analysis. In addition, ADMET properties of products were evaluated in silico and showed high drug similarity. [Display omitted] [ABSTRACT FROM AUTHOR]

• Seven undescribed cycloartane triterpenes isolated from D. binectariferum leaves. • Cytotoxicity evaluation on RAW 264.7 cells and anti-inflammatory potential via inhibition of NO production. Seven undescribed cycloartane-type triterpenes (4 – 10) were isolated from the leaves of Dysoxylum binectariferum. The chemical structures and relative stereochemistry of all cycloartane triterpenes were determined by analysis of 1D and 2D NMR and ESI-HRMS spectroscopic data. Compound 4 was found to be a diastereoisomer of the previously discovered compound 2 (beddomeilactol). The compound 5 was identified as the methyl ester of compound 1 (beddomeilactone). The compounds 6 and 7 were found to be diastereoisomers with only a stereochemical change at C-4 and their absolute stereochemistry established by X-ray analysis. Compounds 6 – 8 and 10 were identified as 3,4-seco-cycloartane type triterpenes, while compound 9 was elucidated as nor -3,4-seco-cycloartane triterpene. Nitric oxide (NO) inhibition was used to assess the anti-inflammatory effects of all newly isolated natural products in LPS-induced RAW 264.7 cell line. It was found that compounds 1, 2, 6 and 8 showed good IC 50 values of 14.98 ± 4.06, 38.50 ± 2.88, 36.95 ± 3.24, and 35.37 ± 4.51 µ M respectively for NO production inhibition and were non-toxic to RAW 264.7 macrophages. Seven undescribed cycloartane triterpenes and their Cytotoxicity evaluation on RAW 264.7 cells and anti-inflammatory potential via inhibition NO production [Display omitted] [ABSTRACT FROM AUTHOR]

• Complete 1H and 13C NMR data of 7‑ tert -pentyl-2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones 5-11 and the updated data of compounds 1-4 at 500 MHz were accounted to comprehend the impact of various alkyl groups on 1. The 1H and 13C NMR chemical shifts of compounds 5-11 were unambiguously assigned using 1H1H– COSY, NOESY, and HMQC spectral studies. • The incorporation of alkyl groups at C-7 of compound 1 leads to the formation of a chair-boat conformer in compounds 2-5 (Me at C-7, 2 ; et at C-7, 3 ; t Bu at C-7, 4 ; t Pe at C-7, 5) as a minor isomer. This is likely due to the presence of bulkier alkyl groups at C-7, which may cause steric hindrance and prevent the formation of the more stable chair-chair conformer. However, by controlled stirring with an improved optimization procedure the formation of chair-boat isomer has been suppressed or nullified. • Product yield and stereochemistry were significantly controlled by optimizing the reaction conditions. • The majority of the compounds were achieved as single isomers with chair-chair conformers despite the bulkier substituents on C-7 and the ortho positions of the phenyl. • Successfully synthesized molecules with specific stereochemistry and conformational properties could have important implications for their potential uses in various biological applications but expressed moderate antioxidant potency by the DPPH method. A series of 7‑ tert -pentyl-2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones (5-11), as well as three reported analogs (1, 2 and 4) were synthesized, and characterized under identical conditions for comparison. The NMR data were assigned using 1H1H– COSY, NOESY, and HMQC spectral studies. The results suggest that all bicyclic compounds exist predominantly or exclusively in the chair-chair conformation, with an equatorial disposition of phenyl/substituted phenyl groups at C-2/C-4 and alkyl groups at C-7. This was observed regardless of the size or nature of the substituents on the phenyl groups and/or cyclohexane. However, in a few compounds, a minor population of the chair-boat conformer was also observed with an equatorial orientation of phenyl/substituted phenyl groups on the piperidine chair and the tert ‑pentyl on the bowsprit orientation of the cyclohexane boat. Lastly, the tert ‑pentyl compounds were screened for their antioxidant potency using the DPPH radical scavenging method, and the results were found to be moderate. [Display omitted] [ABSTRACT FROM AUTHOR]

An unexpected generation of a 5,7-bicyclic framework from 5-aminopyrazoles and 2,5-dimethoxytetrahydrofuran was detected in the synthesis of originally desired 5-pyrrol-1-ylpyrazoles. To gain insight about the structure and behavior of the novel studied compounds, heteronuclear 2D NMR (including 1 H 15 N, 19 F 13 C and 19 F 15 N correlations), single-crystal X-Ray diffraction structural analysis and HR-MS were exploited. Four other syntheses were designed to obtain the pyrazoloazepines by independent reaction pathways which never yielded the desired bicyclic products obtained before. The reaction conditions of the original Clauson-Kaas synthesis were optimized to yield the pyrazoloazepines in reasonable yields. [ABSTRACT FROM AUTHOR]

4- N , N -dimethylamino-4′- N ′-methyl-stilbazolium tosylate (DAST) crystal has excellent properties of nonlinear optics and electro-optical effect, and it can be used in the fields of radiation and detection through wave bands from infrared to terahertz. Besides, DAST thin films have exhibited their excellent properties and have expanded application fields of DAST material. CD 3 OD was chosen as the solvent to conduct 1 H NMR, 13 C NMR, 1 H– 1 H COSY, 1 H– 13 C HSQC and 1 H– 13 C HMBC characterization of DAST respectively. All peaks in 1 H and 13 C NMR spectra of DAST were assigned with assistance of 2D NMR correlation peaks. [ABSTRACT FROM AUTHOR]

• Two pectic fractions were purified from Osmunda japonica Thunb polysaccharides. • WOJP-A-b was a pectic polysaccharide rich in homogalacturonan (HG) regions. • WOJP-A-c was a pectic polysaccharide rich in HG and rhamnogalacturonan I domains. • Osmunda japonica Thunb could provide natural pectin products for functional foods. Osmunda japonica Thunb, as a traditional edible wild herb in China, has a wide range of pharmacological effects. In this study, two pectic polysaccharides, WOJP-A-b and WOJP-A-c, were obtained from O. japonica stalks by water extraction and alcohol precipitation method, and their fine structures were investigated. Monosaccharide composition and molecular weight analyses showed that WOJP-A-b (10.6 kDa) was mainly composed of galacturonic acid (GalA), with less galactose (Gal) and arabinose (Ara) (molar ratio = 68.3: 12.5: 9.0), while WOJP-A-c (6.6 kDa) was primarily composed of GalA, Gal, Ara, and rhamnose (Rha) residues in a molar ratio of 39.4: 41.2: 11.8: 6.8. The results indicated that WOJP-A-b consisted of esterified homogalacturonan (HG) domains, while WOJP-A-c contained HG domains, as well as 1,4- β -galactan and 1,5- α -arabinan, which might be linked covalently to the minor rhamnogalacturonan I (RG-I) domains. The results of this study will provide the basis for structure-activity relationship studies of O. japonica polysaccharides and development of natural functional foods and pharmaceuticals. Acidic polysaccharides (WOJP-A) were obtained from Osmunda japonica Thunb by extraction and isolation, and the major acidic polysaccharide fractions WOJP-A-b and WOJP-A-c were further obtained by isolation and purification, and then both were structurally analyzed, and finally deduced WOJP-A-b consisted of esterified homogalacturonan (HG) domains, while WOJP-A-c contained HG domains, as well as 1,4- β -galactan and 1,5- α -arabinan, which might be linked covalently to the minor rhamnogalacturonan I (RG-I) domains. [Display omitted] [ABSTRACT FROM AUTHOR]

• New thiazole derivatives from natural product (Ammodaucus leucotrichus and Cuminum cyminum) were hemi-synthesized. • Chemical characterization of the obtained compounds was performed using FTIR, 1D and 2D NMR. • DFT calculation study confirmed the structural stability of the obtained compounds. • New thiazole derivatives exhibited moderate antioxidant activity, while their antibacterial one was much more interesting against some bacterial strains. • Molecular docking study revealed that the new thiazole derivatives can be good candidates to inhibit TNF-α. This paper reports the hemi-synthesis of a new thiazole derivatives from 3-allylrhodanine under green chemical conditions (solvent free and ambient temperature). Two targeted molecules: perillaldehyde and cuminaldehyde from essential oils of Ammodaucus leucotrichus Coss. & Dur. and Cuminum cyminum L. were used. Thiazole derivatives (HRP11, 12) were obtained and characterized by FTIR, 1H NMR, 13C NMR, 2D NMR. In addition, stereochemistry of HRP11, 12 was characterized by using 2D NMR and their structural stability was confirmed by DFT calculation. Furthermore, the new products were screened for their in vitro biological activity and in silico interaction with TNF-α by using molecular docking study. A moderate antioxidant activity was found for the two obtained products evaluated by DPPH and ABTS radical scavenging techniques. Against all odds, HRP12 revealed an interesting antibacterial activity against Escherichia coli, Citrobacter freundii , and Salmonella typhimurium. Thereby, a molecular fluorescence spectroscopy was carried out to compare the fluorescence of gentamicin and that of HRP11, 12. Molecular docking performed on the Tumor Necrosis Factor (TNF-α) demonstrated sensitivity towards the thiazole derivatives obtained. [Display omitted] [ABSTRACT FROM AUTHOR]

Potential antimicrobial activities of azabicyclic skeleton based N -cyclohexyl-2-(2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9-ylidene)hydrazinecarbothioamides ( 6 – 10 ) was synthesized. The newly synthesized compounds were characterized by FT-IR, 1 H NMR, 13 C NMR, HRMS and elemental analysis. The synthesized compound 6 was further compared by 2D NMR techniques (HOMOCOSY, NOESY and HSQC). The single crystal XRD study revealed that the compound 6 adopts a twin-chair conformation with equatorial orientation of the aryl groups. Antimicrobial activities have been carried out for compounds 6 – 10 against a panel of bacterial and fungal strains using Streptomycin and Amphotericin B as standards. [ABSTRACT FROM AUTHOR]

• New Pyranonicotinonitrile/Chromene-3-carbonitrile are synthesized from DHA by MCR. • All compounds are fully characterized by 2D NMR and mass spectroscopy. • Antioxidant and antimicrobial activities are evaluated in-vitro. • Molecular docking of PBPs, TMK and z protein are studied on active compounds. [Display omitted] Dehydroacetic acid (DHA) and derivatives are widely used in the synthesis of pharmacologically active heterocyclic compounds. In this study, two new series of pyranonicotinonitriles and chromene-3-carbonitriles have been synthesized under microwave irradiation using DHA synthons, as starting materials, through multicomponent reaction (MCR), involving domino Knoevenagel-Michael addition or one pot intramolecular cyclization. All the resulting heterocyclic compounds have been characterized by 1H NMR and 13C NMR, 2D NMR (HSQC, HMBC) and mass spectroscopy. Mass peaks of the synthetized compounds correspond perfectly to molecular ions [ M + H ] or [ M +Na]. Notably, 1H NMR spectra of all the compounds display a characteristic doublet at δ H 6.07 ppm, which is assigned to the pyran-2-one heterocycle. Biological activities, such as the antioxidant DPPH radical scavenging and antibacterial/antifungal assays against ATCC strains have been evaluated in -vitro. Results showed that all compounds are capable to reduce DPPH with different IC 50 values. The germs sensitivity towards the synthesized compounds is variable with Staphylococcus aureus being the most sensitive bacteria. Further docking simulations have been carried out targeting S. aureus penicillin binding proteins group (PBP2, PBP3 and PBP4) and thymidylate kinase (TMK) and the cell division Z ring protein (FtsZ) using AutoDock Vina software. The validity of docking results have been confirmed based on the best affinity scores and types of interactions. The molecular mechanisms of the synthesized heterocycles towards target proteins involved in S. aureus growth have been predicted through molecular docking studies. [ABSTRACT FROM AUTHOR]

Highlights: [•] Rhenium(V)porphyrins were synthesized. [•] UV–Visible, IR, 1Н, 2D NMR spectra for title compounds were studied. [•] The compounds do not undergo M N bonds dissociation in strong acids. [•] The compounds form the stable π-cation radicals . [ABSTRACT FROM AUTHOR]

Highlights: [•] Site selectivity and regioselectivity of the [2+3] cycloaddition reaction was established by 2D NMR spectroscopy. [•] Outstanding effect of carbohydrate-ytterbium triflate catalysts on selectivity of the reaction was demonstrated. [•] Influence of alkene electron densities on cycloaddition to cyclohexene derivatives was found. [•] Complete 1H and 13C NMR characterization of 3a,4,5,6,7,7a-hexahydro-1,2-benzoxazoles was achieved. [Copyright &y& Elsevier]

Abstract: In this work is described a complete 1H and 13C NMR analysis for a group of four sesquiterpene lactones, three previously unknown. The unequivocal assignments were achieved by 1H NMR, 13C{1H} NMR, J-resolved, gCOSY, gHMQC, gHMBC and NOESY experiments and no ambiguities were left behind. All hydrogen coupling constants were measured, clarifying all hydrogen signals multiplicities. [Copyright &y& Elsevier]

Abstract: Variously substituted 3-azabicyclo[3.3.1]nonan-9-ones viz, 2,4-diaryl-3-azabicyclo[3.3.1]nonan-9-ones, 2,4-diaryl-1-methyl-3-azabicyclo[3.3.1]nonan-9-ones and 2,4-diaryl-7-methyl-3-azabicyclo[3.3.1]nonan-9-ones were conveniently synthesized by a modified and an optimized one-pot Mannich condensation of cyclohexanones, benzaldehydes and ammonium acetate in 1:2:1.5M ratio. All the synthesized bicycles were examined by their physical and spectral (IR, HR-MS, 1H NMR and 13C NMR) techniques. In order to establish their unambiguous stereochemical assignments, H,H-COSY, HET-COSY, HMBC, NOESY and dynamic NMR investigations have been carried out for some of the representative compounds. The detailed NMR analysis proved that all the synthesized 3-azabicycles exist in a twin-chair conformation with an equatorial orientation of the substituents, regardless the incorporation of either linear or bulkier groups on the phenyl and/or methyl on the heterocycle or carbocycle. The electronic effects of methylation on the azabicycle as well as the ortho substitution on the phenyl provided some useful insights. [Copyright &y& Elsevier]

Abstract: A series of thirteen 1-benzyl-3-alkyl-2,6-diarylpiperidin-4-ones 14–26 were conveniently synthesized in high yields 87–92%. In order to find the impact on piperidone stereochemistry, beside the N-benzylation, methyl/ethyl/isopropyl groups at C-3 and halo/alkyl/alkoxy/benzyloxy groups on the phenyl rings at C-2/C-6 were introduced. All the synthesized compounds were characterized by mass, 1H and 13C NMR spectral studies. Of them, the 1-benzyl-3-ethyl-2,6-diphenylpiperidin-4-one 22 was completely characterized by 2D NMR techniques such as 1H 1H COSY, 1H 13C COSY and NOESY to assign the signals, unambiguously. The proton coupling constants and NOE correlations provided the complete stereochemistry of 22, which is further witnessed by its single-crystal XRD analysis. The NMR and XRD studies revealed that the compound 22 exists in a chair conformation with equatorial orientation of all the substituents in both solution and solid states. On the basis of their vicinal coupling constants, the chair conformation with equatorial orientation of the substituents at C-2, C-3, C-6 and N is proposed for all compounds 14–26; moreover, a considerable population of boat conformation also suggested for the compound 26 along with the predominant chair conformation, in solution. [Copyright &y& Elsevier]

Abstract: A complete study of the conformational behavior of cyclopentadecaphane by DNMR and theoretical methods demonstrates that: (a) the macrocycle adopts syn-orientation of indolizine fragments; (b) internal rotation around the bonds between indolizine and quinoxaline moieties produces two strictly different structures in solution: in dominant non-symmetrical form (ca. 67%) the halves of the macrocycle are not equivalent while in the minor symmetrical form (ca. 33%) they can be superimposed by rotation. [Copyright &y& Elsevier]

Abstract: Combined use of 2D NMR correlation methods (1H–13C and 1H–15N 2D HMBC) and the DFT-GIAO chemical shift calculations allows unequivocal determination of structure for novel quinoxaline. Such interplay of experiment and theory is really reliable and convenient way for structure elucidation of complex heterocycles. [Copyright &y& Elsevier]

Methacrylonitrile/butyl acrylate (M/B) copolymers were prepared by bulk polymerization using benzoyl peroxide as an initiator. The Distortionless Enhancement by Polarization Transfer spectra were used to differentiate between the carbon resonance signals of methyl, methine, methylene and oxymethylene groups in the 13C{1H} NMR spectrum of the copolymer (M/B). Comonomer reactivity ratios were determined using Kelen–Tudos and non-linear error in variable methods. Two-dimensional Heteronuclear Single Quantum Coherence and Total Correlated Spectroscopy were used to resolve the complex 1H NMR spectrum and to determine the compositional and configurational sequences of M/B copolymers. [Copyright &y& Elsevier]

Two new cholesteryl 4-alkoxyphenyl-4′-benzoates (CnH2n+1OC6H4C6H4COOCh), where Ch represents cholesteryl moiety and n=10 and 16) have been synthesized and their molecular orientation at ambient temperature were studied. The structure determination on these compounds was performed in solid state by infrared spectroscopy based on vibrational analysis wherein the cholesteryl–phenyl and phenyl–aliphatic carbon linkages were concluded. Their molecular structures were further ascertained through the 1H and 13C NMR spectra along with two-dimensional COSY, NOESY, ROESY, 1H–13C HMQC and HMBC. The long-range connectivity as concluded from the NOESY, ROESY and HMBC spectra together with the related data led to a postulation that the title compounds in the liquid state exist in the conformation whereby the cholesteryl moiety was not lying along the entire molecular long axis. The cholesteryl fragment was presumed to be bent at the ester linkage of O...C–O and the phenyl rings located between cholesteryl and alkoxy chain group are not coplanar. [Copyright &y& Elsevier]

The reconstruction of angular distributions from two-dimensional (2D) magnetic resonance spectra of powders is described. The analysis involves no model assumptions and is applicable to 2D exchange NMR as well as 2D nutation exchange NQR. The proposed method is based on the constrained analysis of selected dominant ridges of a 2D powder spectrum. Practical applications of the proposed technique are demonstrated with experimental 13C 2D exchange NMR spectrum of dimethylsulfone and calculated 35Cl 2D nutation exchange NQR spectra of chloral hydrate. Rotational angle distributions for methyl groups in dimethylsulfone and CCl3 group in chloral hydrate have been found. The chemical shift anisotropy of 13C in dimethylsulfone was determined with high accuracy from 2D exchange NMR powder spectra. [Copyright &y& Elsevier]

Alkylation of some selected [1,2,3]triazolo[4,5-d]pyridazines having five or more nitrogen atoms capable for alkylation was investigated. Pyridyl derivatives substituted also on the [1,2,3]triazole ring gave quaternary pyridinium salts, whereas in the case of the analogues compounds unsubstituted at the triazole moiety, the alkylation of the triazole ring was also observed. Unambiguous structure elucidation was provided by 1H–15N HMBC experiments which also allowed the assignment of the 15N NMR shifts. [Copyright &y& Elsevier]

• A novel chiral (s)-carvone dihydrazone (s-CHD) was hemi-synthetized from the natural (s)-carvone by reacting oxalyldihydrazide (ODH) with caraway's seeds essential oil. • Enantio-pure (s)-carvone dihydrazone (s-CHD) is structurally characterized by Single-crystal X-ray diffraction, 2D-NMR spectroscopy and chiral LCMS analysis. • The (s)-CHD exhibited an antigrowth potential against HepG2, Hela, RAW 264.7 and MCF-7 tumor cell lines without affecting normal cells viability. • Molecular docking shows that (s)-CHD possesses high affinity towards the kinase domain receptors CK2 and EGFRk, being able to bind to the kinase ATP region. Polyfunctional N,O,O,N-type ligands such as the oxalyl dihydrazide (ODH) may induce formation of mono-, di-, and polynuclear complexes with natural monoterpene ketones, involving ligand bridging and Oxo-bridging. In this context, a novel chiral dihydrazone is designed through hemi-synthesis process by reacting oxalyldihydrazide (ODH) with (s)-carvone, the major compound of caraway's seeds essential oil. The C = N imine bi-condensation is performed without prior isolation of the natural (s)-carvone and the resulting (s)-carvone dihydrazone (s-CHD) is structurally characterized by Single-crystal X-ray diffraction, 2D-NMR spectroscopy and chiral LCMS analysis to confirm the formation of a single pure enantiomer. In -vitro cell-based assays were conducted on normal fibroblast (L929) using a presBlue (PB) fluorescence quantification method of cell-viability and by sulforhodamine B calorimetric cytotoxicity assays to determine the anti-proliferative effect on four human tumoral lines (NCI-H460, Hela, HepG2 and MCF-7) and normal PLP2. Anti-inflammatory assays were determined through NO production by Maurine LPS-stimulated macrophages (RAW 264.7). The (s)-CHD has no effect on normal cells viability (>88%) and PLP2 (GI50= 326 ug/mL), while a moderate (∼55%) to significant (∼63%) antigrowth potential was recorded against HepG2, Hela and MCF-7 tumor cell lines, where RAW 264.7 was feebly sensitive. A molecular docking was performed using Autodock vina software on the protein kinase CK2 and Epidermal Growth factor Kinase proteins EGFK and the dock scores allowed to identify significant binding affinities (lower ΔG and Ki values) and potential hydrophilic/hydrophobic interactions with (s)-CHD comparing to the clinical ellipticine as potential ligands. Molecular docking suggests that (s)-CHD possesses high affinity towards the kinase domain receptors CK2 and EGFR, being able to bind to the ATP region. [ABSTRACT FROM AUTHOR]

• The effect of 1,3 allylic interaction between the oxime oxygen and H-5e has been observed with the help of 2D NMR. • Single crystal XRD analysis confirms C−H···Cl interaction majorly present in the crystal packing. • The Quantum Chemical calculations were performed using DFT/B3LYP/6-311 G (d, p) level of theory. • HOMO, LUMO energies, Molecular Electrostatic Potential (MEP) and Fukui functions were calculated. The 1H and 13C NMR spectra of five 4,8,9,10-tetraaryl-1,3-diazaadamantan-6-one O-methoxy oximes were recorded. The chemical shifts, conformation, orientation of the aryl groups and effect of 1, 3 allylic interactions were analyzed using COSY, NOESY, HSQC and HMBC spectral data. These studies propose that the reported compounds exhibit twin-chair conformations with the axial and equatorial orientation of the aryl groups. The proposed conformation and aryl group orientations are unambiguously confirmed by single-crystal X-ray diffraction analysis. In the crystal, one C−H···Cl hydrogen-bonding and two C−H···π interactions were present between the asymmetric unit. Many types of C−H···Cl, C−H···π and π···π intermolecular interactions interconnects two asymmetric units to form a three-dimensional framework. The analysis of Hirshfeld surface and fingerprint plots indicates the dominance of Cl···H (36.6 %) and H···H (36.3 %) contacts to the overall packing arrangement. The molecular reactivity and electron density descriptors HOMO, LUMO, MEP and Fukui functions are calculated using DFT calculation of the studied O-methoxy oximes 3a–3e. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• Five new 2 r ,4 c -diaryl-7-(t -butyl)-3-azabicyclo[3.3.1]nonan-9-ones (P1–P5) have been synthesized. • Conformational analyses have been carried out using NMR spectra. • Conformational analysis shows that the product exist in two isomers. • The major isomer adopts twin-chair conformation with equatorial orientations of the aryl and t -butyl groups. • The minor isomer adopts chair-boat conformation with equatorial orientations of the aryl groups and the t -butyl group in the bowspirit position. 2,4-Diaryl-7-(t -butyl)-3-azabicyclo[3.3.1]nonan-9-ones have been synthesized by the reaction of 4- t -butylcyclohexanone with five different aromatic aldehydes and ammonium acetate. 1H and 13C NMR spectra have been recorded for the products in all the five cases. 1H-1H COSY, NOESY, HSQC and HMBC spectra have been recorded for the product obtained using p -isopropylbenzaldehyde. The NMR spectra suggest that the product contains two isomers. The spectral data suggest that the major isomer is 2 r ,4 c -diaryl-7 c -(t -butyl)-3-azabicyclo[3.3.1]nonan-9-one adopting twin-chair conformation with equatorial orientations of the aryl and t -butyl groups. The major isomers are termed as 1, 2, 3, 4 and 5. The minor isomer is 2 r ,4 c ,diaryl-7 t - (t -butyl)-3-azabicyclo[3.3.1]nonan-9-one adopting chair-boat conformation with equatorial orientations of the aryl groups and t -butyl group in the bowspirit position. The minor isomers are termed as 1′, 2′, 3', 4' and 5′. Single crystal has been obtained from the product when aryl is p -methoxyphenyl. X-Ray crystallographic study of this crystal shows that it is the major isomer 3 adopting twin-chair conformation with equatorial orientations of the p -methoxyphenyl and t -butyl groups. The formation of minor isomer suggests that 4- t -butylcyclohexanone exists in boat conformation with the t -butyl group in the bowspirit position to some extent. Image, graphical abstract [ABSTRACT FROM AUTHOR]

This study explored the rearrangement process which occurred during Grignard reactions of the pentacycloundecane (PCU) dione, 1. This compound was reacted with vinyl and allyl magnesium bromide to afford PCU-vinyl cyclic ether, 2 , and PCU-allyl cyclic ether, 4 , which upon ozonolysis afforded compounds PCU dilactone, 3 and PCU-cyclic ether monoacid, 5 respectively. This resulted in the discovery of three novel cage compounds, 2 , 4 and 5. The Baeyer-Villiger oxidation of 1 was proposed and investigated experimentally as an alternative synthetic route for the PCU dilactone. The unsymmetrical nature of compounds 2 , 4 and 5 resulted in overlapping signals of the methine protons and carbons observed in the 1H and 13C NMR spectra, however, the complexity of the spectra was resolved by using 2D NMR techniques to successfully elucidate these compounds. Herein, the three novel cage compounds including compound 3 were fully characterized by IR and NMR spectroscopy, HRMS. Single crystal X-ray crystallography analysis was also performed on compounds 3 and 5. • 2D NMR is essential to the elucidation of overlapping polycyclic 'cage' proton NMR signals. • X-ray crystal structure of pentacycloundecane supports 1D and 2D NMR elucidation. • Elucidation of polycyclic molecules using NMR techniques. • NMR Elucidation of Pentacycloundecane and its derivatives. [ABSTRACT FROM AUTHOR]

An interesting iodine/methanol mediated rearrangement of tetraaylpiperidin-4-ones to 2-methoxy-2,4,5-triaryl-1 H -pyrrole-3-ones is described. The structural features of the products are investigated by spectral data and single crystal X-ray analysis. The antifungal, antibacterial and antioxidant characteristics of the synthesized compounds have been studied. Image 1 • Conversion of tetraarylpiperidin-4-ones to 5-aryl-2-methoxy-2,4-diphenyl-pyrrole-3-ones in presence of I 2 /MeOH is reported. • The mechanism for the ring contraction rearrangement is proposed. • Synthesized new compounds have been characterized by 1D, 2D NMR and SC-XRD techniques. • Synthesized new compounds exhibit good antimicrobial, antifungal and antioxidant properties. [ABSTRACT FROM AUTHOR]