bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid Solvent Extraction of Tin(IV) with High Molecular Weight Amine from Hydrochloric Acid Solution
Authors: Sargar B. M. , Anuse M. A. 
Published: May 2015

AbstractA novel method has been developed for the solvent extraction of tin(IV) from 8 M hydrochloric acid with 4% N‐n‐octylaniline. Tin(IV) from the organic phase was determined spectrophotometrically with pyrocatechol violet at 550 nm. Extraction was found to be quantitative in the range of 7–10 M hydrochloric acid. When the concentration of N‐n‐octylaniline was varied from 0.05–20% in xylene, it showed that optimum concentration was > 3%. Amongst diluents like benzene and xylene, toluene was found to be an effective diluent. Effect of shaking time, concentration of metal ion, and salting out agents was studied.Tolerance limits of various diverse ions were determined by masking interfering cations. Tin(IV) was separated from associated elements in its binary mixture with Se(IV), Sb(III), Bi(III), Pb(II), Au(III), Cu(II) and Zn(II) and from its ternary mixtures with Sb(III), Bi(III) and Cu(II), Au(III). The proposed method was applied for separation and determination of tin(IV) in tin bearing alloys and foodstuffs.
Vapor‐Phase Reaction of Citronellal over Mesoporous Molecular Sieves MCM‐41 and Zeolites
Authors: Shieh Dong‐Lin , Tsai Chia‐Chun , Chen Chih‐Wei , Ko An‐Nan 
Published: May 2015

AbstractThe vapor‐phase reaction of citronellal (CTN) at 220 °C and atmospheric pressure has been studied using mesoporous molecular sieves and zeolites in a fixed‐bed reactor. The primary products included isopulegol (IPG), menthone, and pulegol with subsequent reactions to form cyclic hydrocarbons. The CTN conversion and the product selectivity depend on the acidity and the textural property of catalysts. Lewis and/or Brönsted acid sites are essential for catalyzing this reaction. An increase of SiO2/Al2O3 mol ratio diminishes the acid amount of all catalysts and enhances both the surface area and the structural order of MCM‐41. The catalytic activity follows the order of MCM‐41 > HZSM‐5 > Hβ > USY, in accordance with the relative total acid amount except that of MCM‐41. Despite its low acidity, Si‐MCM‐41 exhibits the best catalytic performance due to its uniform mesopores, large surface area and good stability; the CTN conversion and the IPG yield attain 91.9% and 58.6%, respectively, after at least 25 h time‐on‐stream.
An Efficient and Simple Approach to Predict Kovat's Indexes of Polychlorinated Naphthalenes in Gas Chromatography
Authors: Yin Chunsheng , Liu Shushen , Wang Xiaodong , Chen Da , Wang Liansheng 
Published: May 2015

AbstractMolecular structures of polychlorinated naphthalenes were numerically described with a simple but efficient encoding method. Correspondingly a set of structural parameters were obtained for these compounds and linearly correlated with their gas chromatography retention indexes. A quantitative structure‐retention relationship Model (M1) was developed by using multiple linear regression (MLR) with correlation coefficient R = 0.9880 between the numeric structural codes and the gas chromatography retention indexes of 62 polychlorinated naphthalenes. If the “leave‐one‐out” cross‐validation procedure was employed to construct QSPR model for all samples, the second model M2 with the correlation coefficient being R = 0.9839 was generated. The structural codes of polychlorinated naphthalenes were tested with MLR for estimation and prediction of the GC RI by models M1 and M2, and the results obtained were satisfactory.
The Structure of 2‐[(1S)‐(+)‐10‐camphorsulfonamino]‐6‐aminopyridine in the Solid State and in Solution; Unprecedented Cocrystallization of Four Stereoisomers
Authors: Chen Tsun‐Ren , Wu Ying‐Yann , Chen Jhy‐Der , Keng Tai‐Chiun , Wang Ju‐Chun 
Published: May 2015

AbstractThe solid and solution structures of a new optically active aminopyridine compound, 2‐[(1S)‐(+)‐10‐camphorsulfonamino]‐6‐aminopyridine [(S)‐csaap], 1, are reported. Crystal data: space group P21, a = 8.9729 (5), b = 10.9447 (6), c = 36.693 (2) Å, β = 96.435 (1)°, V = 3580.8 (3) Å3, Z = 8, R1 = 0.0673 and wR2 = 0.1600 with I > 2σ(I). This chiral compound shows an unprecedented cocrystallization of four stereoisomers, which are characterized by X‐ray crystallography and NMR spectroscopy.
Reactions of Polymer‐Supported α‐Selenoaldehydes with Grignard Regents. A Facile Solid‐Phase Stereoselective Synthesis of (E)‐1,2‐Disubstituted Ethenes
Authors: Sheng Shou‐Ri , Huang Xian 
Published: May 2015

AbstractPolymer‐supported α‐selenoaldehydes easily obtained by reaction of polymer‐supported 4‐(phenylseleno)morpholine with aldehydes react with Grignard reagents to form polymer‐supported β‐hydroxyalkyl selenides, which were treated with thionyl chloride/triethylamine leading to (E)‐1,2‐disubstituted ethenes in good yields.
Intramolecular [2+2] Photocycloaddition‐Fragmentation: Facile Entry to a Novel Tricyclic 5‐6‐7 Ring System
Authors: Hong Bor‐Cherng , Chen Shang‐Hung , Kumar Ellappan Sampath , Lee Gene‐Hsiang , Lin Kuan‐Jiuh 
Published: May 2015

AbstractAn expeditious route to a novel 5‐6‐7 tricyclic ring system is described. The chemistry capitalizes on an enantioselective glyoxylate‐ene reaction, enzymatic resolution as well as a [2+2] photocycloaddition‐fragmentation.
Insertion Reactions of Carbon Disulfide into Mg‐C and Mg‐N Bonds: Syntheses and Structural Determinations of Mg(S2CY)2(THF)n(Y=NEt2, NiPr2, iPr, Ph) and BrMg(S2CZ)(THF)3(Z=Ph, iPr)
Authors: Chang Chung‐Cheng , Yang Kuo‐Ching , Guo Jeng‐Gong , Huang Leigh‐May , Wang Li‐Chyung , Lee Gene‐Hsiang , Peng Shie‐Ming 
Published: May 2015

AbstractThe insertion reaction of CS2 with Mg(NR2)2 (R= Et, iPr), MgR′2 (R′= Et, Ph) and R″MgBr (R″= iPr, Ph) respectively lead solid products, Mg(S2CNR2)2(THF)n (1: R= Et, n=2; 2: R= iPr, n=1), Mg(S2C′R)2(THF)2 (3: ′R= Et, 4: ′R= Ph), BrMg(S2C″R) (THF)3 (5: ″R= iPr, 6: ″R= Ph) in which the inserted carbon disulfides act as terminal chelating ligands. These compounds were characterized with 1H, 13C NMR, IR spectroscopy, mass spectrometry, elemental analyses, and X‐ray crystallography.
Corrosion Behavior of Carbon Steel in Lithium Bromide Solution
Authors: Huang Nai‐Bao , Liang Cheng‐Hao 
Published: May 2015

AbstractWeight‐loss tests and electrochemical techniques are used to study the inhibition of BTA and Na2MoO4 either individually or in different combinations for carbon steel in boiling 10.24 mol/L LiBr solution containing 0.07 mol/L LiOH. The result indicates the corrosion of carbon steel is effectively inhibited when BTA or Na2MoO4 is added to the solution individually. The adsorptions of BTA or Na2MoO4 on carbon steel surfaces can be well fitted to a Langmuir adsorption isotherm. The free energy of adsorption of BTA and Na2MoO4 are −45.07 kJ/mol and −40.69 kJ/mol, respectively. The corrosion rate is decreased to the minimal value, which is 8.39 μm/y, when 7.28 × 10−4 mol/L Na2MoO4 and 8.39 × 10−4 mol/L BTA are added to a 10.24 mol/L LiBr solution containing 0.07 mol/L LiOH. The inhibition mechanism of the above mixed inhibitors results from the complemental effect of the compact inner layer film composed of Fe‐BTA and the absorbed MoO42− in small quantity of the active site and the outer layer. The passive film of the coordination compound and the adsorbed MoO42− prevent Br− from absorbing and effectively decrease the corrosion of carbon steel.
Synthesis of Lithiophorite in High Alkaline Conditions
Authors: Yang Deng‐Shiu , Wang Ming‐Kuang , Chang Chia‐Ming , Sheu Hwo‐Shuenn , Hwang Bing‐Joe 
Published: May 2015

AbstractLithiophorite consists of alternatively stacked MnO6 octahedral sheets and LiAl2(OH)6 octahedral sheets. Its applications in laboratories and industries have been hindered by sophisticated operation procedures, long reaction time, or impurities existing in the final product. We proposed a fast and simple method, mixing birnessite, aluminate and lithium hydroxide together (designated it as the BAL method) in high alkaline conditions (pH > 13), and treating it hydrothermally at 423 K for 6 hours to prepare pure lithiophorite. A specific reaction between lithium cations and aluminate anions plays as a key role in the BAL method. Due to this specific reaction, LixAln(OH)m+z complexed cations can form and penetrate into interlayers of birnessite to replace sodium cations. In high alkaline conditions (pH > 12), LixAln(OH)m+z complexed cations become smaller and are soluble. Thus, the higher alkaline LixAln(OH)m+z complexed cations can penetrate into interlayers of birnessite at a higher rate. Furthermore, impurities, such as lithium intercalated gibbsite (LIG), aluminum oxyhydroxides and aluminum hydroxides are not stable in high alkaline conditions. Consequently, pure lithiophorite can be easily obtained within 6 hours in high alkaline conditions.
Benzolignanoid and Polyphenols from Origanum Vulgare
Authors: Lin Yun‐Lian , Wang Chuen‐Neu , Shiao Young‐Ji , Liu Tzu‐Ying , Wang Wan‐Yi 
Published: May 2015

AbstractA new dihydrobenzodioxane derivative, origalignanol (10), together with nine polyphenolic compounds, salvianolic acid A (1), salvianolic acid C (2), lithospermic acid (3), apigenin 7‐O‐β‐D‐glucuronide (4), apigenin 7‐O‐β‐D‐(6″‐methyl)glucuronide (5), luteolin, (6), luteolin 7‐O‐β‐D‐glucopyranoside (7), luteolin 7‐O‐β‐D‐glucuronide (8), and luteolin 7‐O‐β‐D‐xylopyranoside (9), were isolated from the aqueous ethanolic extract of the aerial parts of Origanum vulgare for the first time. The structure of new compound 10 was determined on the basis of spectroscopic methods. Compound 5 is probably an artifact formed during the isolation. Compounds 1, 2 and 3 showed strong DPPH radical scavenging activity with an EC50 of 7.2 ± 0.4, 9.6 ± 0.9, and 9.5 ± 0.7 μM, respectively, and protected rat hepatocytes from CCl4‐damage at 100 μM.
Stereoselectivity in Diphos Addition to Molybdenum Complex with Pyridine‐2‐thionate (pyS) and η3‐Methallyl Coordinated Ligands
Authors: Yih Kuang‐Hway 
Published: May 2015

AbstractThe conformational isomers endo‐ and exo‐[Mo{η3‐C3H4(CH3)}(η2‐pyS)(CO)(η2‐diphos)] (diphos: dppm = {bis(diphenylphosphino)methane}, 2; dppe = {1,2‐bis(diphenylphosphino)ethane}, 3) are prepared by reacting the double‐bridged pyridine‐2‐thionate (pyS) complex [Mo{η3‐C3H4(CH3)}(CO)2]2(η1:η2:μ‐pyS)2, 1 with diphos in refluxing acetonitrile. Stereoselectivity of the methallyl, C3H4(CH3), ligand improves the formation of the exo‐conformation of 2 and 3. Orientations and spectroscopy of these complexes are discussed.
Rapid Preparation and Easy Quality Control Procedures for 99mTc‐Tin‐Nano Colloid: A Lymphoscintigraphic Agent
Authors: Rashid Haroon , Shah Syed Qaiser 
Published: May 2015

Abstract99mTc‐Tin‐nano colloid is a radiopharmaceutical that can be useful in evaluation of the patients with breast cancer. The current method for preparation requires a lengthy boiling water bath procedure, and the recommended quality control procedure is cumbersome and time consuming. Using a microwave oven, the heating time necessary to provide a maximum labeling efficiency has been reduced to 10 second. A new mini paper chromatography (MPC) system has been developed to analyze the radiochemical purity (RCP) of the labeled preparation involving two different developing solvents. The recommended thin layer chromatography (TLC) system involving the use of an Al2O3 coated plate requires an average time for drying and development of 34.5 ± 0.44 min (n = 30) to complete, whereas the new MPC system has an average developing time of 2.1 ± 0.2 min (n = 20). For RCP values the MPC and TLC methods are correlated closely (r = 0.94). The combined use of the microwave oven heating method and over quick quality control system will facilitate the rapid emergency use of 99mTc‐Tin‐nano colloid.
Study on the Impedance Characteristic and Electrocatalytic Activity of Platinum‐Modified Polyaniline Film
Authors: Niu Lin , Li Qiuhong , Chen Xiao , Wei Fenghua , Wang Hao , Zhang Hu 
Published: May 2015

AbstractThe composite electrode of platinum‐modified polyaniline film is formed in 0.5 M H2SO4 + 3 mM H2PtCl6 solution by cyclic potential or constant potential deposition of platinum particles in polyaniline film. To make a comparison, the polyaniline film with the same initial thickness and structure is also treated with the cyclic potential or constant potential polarization in 0.5 M H2SO4 solution. The electrochemical impedance spectroscopy (EIS) of the composite electrode of platinum‐modified polyaniline film is studied in sulfuric acid solution and compared with the EIS of the polyaniline film without platinum dispersion. The results show that the different modes of potential polarization affect greatly the nature and distribution of the platinum particles, instead of the structure of the polyaniline film (matrix). The electrode reaction kinetics and mass transport process parameters involving charge transfer resistance (Rct), double layer capacitance (Cdl), constant phase elements (CPE) and Warburg impedance in platinum substrate/platinum‐modified polyaniline film/solution interface are discussed on the basis of the interpretation of the characteristic impedance spectra and connected to the electrocatalytic activity on the oxidation of methanol molecules.
Juncenolide E, A New Briarane from Taiwanese Gorgonian Junceella Juncea
Authors: Shen Ya‐Ching , Lin Yu‐Chi , Huang Yeh‐Li 
Published: May 2015

AbstractIn addition to junceellolides B (3) and C (4), a new briarane, juncenolide E (1) has been isolated from the acetone extract of the red gorgonian Junceella juncea, collected on the southern coast of Taiwan. The structure of juncenolide E was determined by interpretation of MS, COSY, HMQC, HMBC and NOESY spectra.
Kinetic Determination of GA by the BZ Oscillating Chemical System
Authors: Dong Yanjie , Gai Ke , Gong Xinxing 
Published: May 2015

AbstractA new analytic method for the determination of gibberellic acid (GA) by perturbation causing different amounts of GA on the BZ oscillating chemical system involving the Mn(II)‐catalyzed reaction between L‐alanine, potassium bromate, and malonic acid in the acidic medium is proposed. The method relies on the linear relationship between the change in the oscillating period of the chemical system and the concentration of GA, which is in this work exposed for the first time. The calibration curve is linearly proportional to the concentration of GA over the range 1.0 × 108 −1.0 × 10−6M, where the regression coefficient is 0.9998, and the detection limit is 5.0 × 10−9 M of GA. Some aspects of the potential mechanism of action of GA on the BZ oscillating chemical system are discussed in detail.
A Novel Macrocyclic Nickel(II) and Ferricyanide 1D Zigzag Chain: Synthesis, Crystal Structure, and Magnetic Properties
Authors: Zhao Qihua , Wang Qinghua , Fang Ruibin 
Published: May 2015

AbstractA novel cyan‐bridged macrocyclic nickel complex [{NiL1}{Fe(bipy)(CN)4}]2·5H2O 1 (L1 = 3,10‐dimethyl‐1,3,6,8,10,12‐hexaazacyclotetradecane, bipy = 2,2‐bipyridine) was synthesized and structurally characterized. The complex exhibits one‐dimensional zigzag chain structures. Each ferrous(II) ion connects two nickel(II) ions using two trans CN− groups, and the remaining CN− groups are terminal. Magnetic measurement shows weak ferromagnetic interaction between the nearest Ni(II) ions through the diamagnetic Fe(II) ion.
Simultaneous Determination of Tin, Nickel, Lead, Cadmium and Mercury in Tobacco and Tobacco Additives by Microwave Digestion and RP‐HPLC Followed by On‐Line Column Enrichment
Authors: Chen Zhangyu , Yang Guang‐Yu , Wang Shuhua , Li Ling , Su Qingde 
Published: May 2015

AbstractA new method for the simultaneous determination of five heavy metal ions, tin, nickel, lead, cadmium and mercury ions as metal‐tetra‐(2‐aminophenyl)‐porphyrin (T2APP) chelates was developed using reversed‐phase high performance liquid chromatography (RP‐HPLC) equipped with a photodiode array detector and combined with an on‐line enrichment technique. The tin, nickel, lead, cadmium and mercury ions were pre‐column derivatized with T2APP to form color chelates. The Sn‐T2APP, Ni‐T2APP, Hg‐T2APP, Cd‐T2‐APP and Pb‐T2APP chelates can be absorbed onto the front of the enrichment column when they are injected into the injector and sent to the enrichment column [Waters Xterra™ RP18(5μ, 3.9 × 20 mm)] with a buffer solution of 0.05 mol/L pyrrolidine‐acetic acid (pH = 10.0) as mobile phase. After the enrichment had finished, by switching the six‐port switching valves, the retained chelates were back‐flushed by mobile phase and traveling towards the analytical column. These chelates separation on the analytical column [Waters Xterra™ RP18 (5μ, 3.9 × 150 mm)] was satisfactory by gradient elution with methanol (containing 0.05 mol/L pyrrolidine‐acetic acid buffer salt, pH = 10.0) and acetone (containing 0.05 mol/L pyrrolidine‐acetic acid buffer salt, pH = 10.0) as mobile phase. The linearity range is 0.01˜120 μg/L for each metal ion. The detection limits (S/N = 3) of tin, nickel, lead, cadmium and mercury are 4.0 ng/L, 3.5 ng/L, 2.5 ng/L, 3.0 ng/L and 3.0 ng/L, respectively. This method was applied to the determination of tin, nickel, lead, cadmium and mercury ions in tobacco and tobacco additives with good results.
A Spectrophotometric Investigation of the Interaction of Iodine with Dibenzyldiaza‐18‐crown‐6, Aza‐15‐crown‐5 and N‐phenylaza‐15‐crown‐5 in Chloroform Solution
Authors: Shamsipur Mojtaba , Pouretedal Hamid Reza 
Published: May 2015

AbstractThe complex formation reactions between iodine and DBzDA18C6, A15C5 and N‐phenylA15C5 have been studied spectrophotometrically in chloroform solution. In the case of DBzDA18C6 is the resulting 1:2 (ligand…I+)I3−, while, in the case of A15C5 and N‐phenylA15C5 a 2:2 molecular complex of [(ligand)2…I+]I3− type was formed. The spectrophotometric results indicate that gradual release of triiodide ion from its contact ion paired form in the molecular complex into the solution is the rate‐determining step of the reaction. The kinetic rate constants for the complexation reactions were determined at different temperatures, and activation parameters were calculated from Arrhenius and Eyring equations.
Friedel‐Crafts Benzylation of Arenes over Mixed Oxides
Authors: Jadhav Sujit R. , Sawant Manohar R. 
Published: May 2015

AbstractThe replacement of liquid acid catalyst by solid acids for the Friedel‐Crafts reaction of aromatic alkylation is a challenging task. Mixed oxide possessing spinel structures were found to catalyze the Friedel‐Craft benzylation of arenes. It was found that the reaction was very fast at 80 °C, hence the reaction was studied with respect to more substrate. The significant point was even at this temperature monobenzylation, with the para isomer predominating, was achieved. Mixed oxides were prepared by co‐precipitation method and were characterized by XRD technique.
Spectrophotometric Determination and Kinetic Studies of Condensation of Aromatic Aldehydes with 7,9‐Dioxo‐6,10‐dioxaspiro[4.5]decane
Authors: Medien H. A. A. , Zahran A. A. , Erian A. W. 
Published: May 2015

AbstractThe condensation reaction rates of 7,9‐dioxo‐6,10‐dioxaspiro[4.5]decane with aromatic aldehydes in chloroform in the presence of piperidine has been investigated spectrophotometrically at 25–50 °C. The reaction follows overall second order kinetics, first order in each of the reactants and zero order with respect to piperidine. The rate of condensation increases with the presence of electron withdrawing groups on the aromatic ring of the aldehyde. From the dependence of the rate constants on temperature, activation parameters have been calculated. Plot of ΔH# versus ΔS# for the reaction gave a good straight line with an isokinetic temperature of 367.55 K. Based on this reaction, determination often aromatic aldehydes in a concentration range of 2.65–69.2 μg/mL is proposed.
Benzoannulation of Quinones by a Cycloaddition‐Fragmentation Approach. A Simple Synthesis of Methoxycarbonyl‐Substituted Polyacenoquinones
Authors: Chou Teh‐Chang , Hsu Chia‐Jung , Chen Jao‐Yu 
Published: May 2015

AbstractThe cycloadducts 2A‐5A obtained from the Diels‐Alder cycloadditions of 1,2,3,4‐tetrachloro‐4,5‐dimethoxycyclopentadiene (1) with p‐benzoquinone (2), 1,4‐naphthoquinone (3), 1,4‐anthraquinone (4), and 2,3‐dicyano‐1,4‐benzoquinone (5) were subjected to the reaction with triethylamine in dichloromethane at room temperature. Cycloadducts 2A and 5A enolized to give the corresponding hydroquinones 2B and 5B, which were oxidized with DDQ to afford naphthoquinone ester 2D and anthraquinone ester 5D, respectively. In the cases of cycloadducts 3A and 4A, the enolization occurred concurrently with oxidation and fragmentation to produce directly the polyacenoquinone esters 3D and 4D, respectively. Under the same reaction condition, the unsymmetrical cycloadduct 6A derived from naphthoquinone ester 2D and 1 yielded isomeric polyacenoquinone esters 6Da and 6Db in a ratio of about 8:1.
Novel Polyhydroxysteroids from the Formosan Soft Coral Sarcophyton Glaucum
Authors: Wang Guey‐Horng , Su Jui‐Hsin , Chen Chien‐Ting , Duh Chang‐Yih , Dai Chang‐Feng , Sheu Jyh‐Horng 
Published: May 2015

AbstractTwo novel polyhydroxysteroids, (24S)‐24‐methylcholestane‐3β,5α,6β,25ξ;,26‐pentol 26‐n‐decanoate (1), (24S)‐24‐methylcholestane‐3β,5α,6β,25ξ;,26‐pentol 25,26‐diacetate (2), and three known sterols (3‐5), have been isolated from a Formosan soft coral Sarcophyton glaucum. The molecular structures of these compounds were determined by spectral methods. The cytotoxicity of these compounds toward various cancer cell lines has also been determined.
Triterpenoid Constituents of Borreria Articularis
Authors: Mukherjee K. S. , Mukhopadhyay B. , Mondal S. , Gorai D. , Brahmachari G. 
Published: May 2015

AbstractThe chloroform extract of the aerial parts and roots of Borreria articularis yielded a new triterpene, 3α‐acetoxy‐oleana‐12‐en‐29‐oic acid along with β‐amyrin. The structures were established by means of spectral as well as chemical studies.
1H NMR Study of Hindered Internal Rotation of Tetramethylthiuram Disulfide in Binary Dimethyl Sulfoxide‐Chloroform Mixtures
Authors: Bordbar Maryam , Bijanzadeh Hamid Reza , Alizadeh Naader 
Published: May 2015

AbstractHindered internal rotation about the C‐N single bonds joining the thiuram disulfide was studied by 1H NMR complete line‐shaped analysis in different dimethyl sulfoxide‐chloroform (DMSO‐CDCl3) mixtures. From the temperature dependence of methyls proton spectra, activation parameters (Ea, ΔH≠, ΔS≠, and ΔG≠) were obtained. The Arrhenius plots showed a distinct isokinetic temperature at about 35 °C at which the exchange rate is more or less independent of the solvent composition. The resulting ΔH≠ against TΔS≠ plot showed a firmly good linear correlation, indicating the existence of an enthalpy‐entropy composition in an exchange process.
Facile Total Synthesis of (±)‐Nimbiol
Authors: Du Zhen‐Ting , Yue Guo‐Ren , Li An‐Pai , Ma Jun‐Ying , Wu Tong‐Xing , She Xue‐Gong , Pan Xin‐Fu 
Published: May 2015

AbstractA facile total synthesis of (±)‐nimbiol 1 has been achieved. In order to decrease the dioxo byproduct 2a, an improved oxidation system of CrO3/H2O/HOAc/NaOAc was used.
Solvent‐free Oxidation of Alcohols by Silica Sulfuric Acid/Sodium Dichromate Dihydrate or Potassium Permanganate/Wet SiO2 System
Authors: Mirjalili Bibi Fatemeh , Zolfigol Mohamad Ali , Bamoniri Abdolhamid , Zarei Amin 
Published: May 2015

AbstractA combination of silica sulfuric acid and sodium dichromate dihydrate or potassium permanganate in the presence of wet SiO2 was used as an effective oxidizing agent for oxidation of alcohols to their corresponding aldehydes or ketones in solvent free conditions.