Terpenoid chemistry. XXIV. (1R)-1-Methoxymyodesert-3-ene, an Iridoid Constitutent of Myoporum deserti (Myoporaceae)

1980 ◽  
Vol 33 (4) ◽  
pp. 853 ◽  
Author(s):  
HG Grant ◽  
PJ O'Regan ◽  
RJ Park ◽  
MD Sutherland
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrochloric Acid ◽  
Essential Oil ◽  
Phthalic Acid ◽  
Room Temperature ◽  
Chromic Acid ◽  
Spectral Studies ◽  
Cyclic Acetal ◽  
Common Variety ◽  
Substituted Furans

A common variety of Myoporum deserti A. Cunn. (Ellangowan Poison Bush) yields an essential oil consisting largely of the iridoid monoterpene, (1R)-1-methoxymyodesert-3-ene, C11H18O2,(1R,4aS,7R,7aR)-1-methoxy-4,7- dimethyl-1,4a,5,6,7,7a-hexahydrocycopenta[c]pyran, b.p. 67°/2 mm,[α]D- 165°. This cyclic acetal is hydrolysed to methanol and a mixture of two epimeric cyclopentanoid dialdehydes which are oxidized to the two epimeric trans,trans-nepetalinic acids and yield (+)-(R)-actinidine with Brady's reagent. (1R)-1-Methoxymyodesert-3-ene is oxidized by ozone/hydrogen peroxide to (1R,2R,5R)-2-acetyl-5- methylcyclopentanecarboxylic acid. Hydrogenation yields mainly (1R)- methoxymyodesertan, hydrolysed by aqueous maleic acid at room temperature to methanol and a cyclic hemiacetal, (1R,4R,4aR,7R,7aR)- 4,7-dimethyl-1,3,4,4a,5,6,7,7a-octahydrocyclopenta[c]pyran-1-ol. Oxidation of this cis,cis-hemiacetal by bromine in acetate buffer yields a lactone further oxidized by chromic acid to (2R,1'S,2'R,3'R)- 2-(2'-carboxy-3'-methylcyclopentyl)-propionic acid.��� (1R)-1-Methoxymyodesertan, refluxed with aqueous phthalic acid, yields (+)-(4R,4aR,7R)-4,7-dimethyl-3,4,4a,5,6,7-hexahydrocyclopenta[c]pyran. Treatment of the hexahydropenta[c]pyran, the cis,cis-hemiacetal or (1R)-1-methoxymyodesertan with hydrochloric acid yields a trans,trans-hemiacetal, (1R,4R,4aR,7R,7aS)-4,7-dimethyl- 1,3,4,4a,5,6,7,7a-octahydrocyclopenta[c]pyran-1-ol, which equilibrates in solution to a mixture of α- and β-anomers. Spectral studies of these and otherproducts establish the configuration of the natural product at C1.��� (1R)-1-Methoxymyodesert-3-ene is not toxic to sheep as are the β- substituted furans characteristic of most other chemovarieties of M. deserti.

scholarly journals The phenomena arising from the addition of hydrogen peroxide to the sol of silicic acid

1927 ◽  
Vol 114 (768) ◽  
pp. 517-521
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrochloric Acid ◽  
Sodium Silicate ◽  
Silicic Acid ◽  
Room Temperature ◽  
Gas Bubbles ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Usual Manner ◽  
Acid Gel

The formation of gas bubbles in silicic acid gel (or, in fact, any gel) has been described by Hatschek, and he expresses the view that “such bubbles, which can be produced by a variety of means, are always lenticular, while gas bubbles in a liquid at rest—however viscous—are, of course, spherical. It is possible to produce such bubbles during the transformation, and to note an abrupt change from the spherical to the lenticular shape, which, as stated, cannot be explained by a mere increase in viscosity.” Experimental. Preliminary Experiment. Bubbles were caused to form in the gel of siliic acid in the following manner:— A mixture of equal volumes of sodium silicate solution (D = 1·15) and hydrochloric acid (3N) was prepared in the usual manner (by using solutions of such concentrations as would cause gelation in 1 to 2 hours). After the mixture had cooled down to room temperature, 2 c.c. of twenty-volume hydrogen peroxide solution were added and the resulting mixture allowed to stand. The experiment was carried out in a small rectangular vessel to facilitate observation.

A One Step Synthesis of New 4-Aminopyrimidine Derivatives: Preparation of Tetrazolo- and s-Triazolopyrimidines

1983 ◽  
Vol 38 (12) ◽  
pp. 1686-1689 ◽  
Author(s):  
Hamed A. Daboun ◽  
Ahmed M. El-Reedy
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrochloric Acid ◽  
Hydrazine Hydrate ◽  
Aromatic Aldehyde ◽  
Methyl Iodide ◽  
Nitrous Acid ◽  
Carbon Disulphide ◽  
Aromatic Aldehydes ◽  
Spectral Studies ◽  
One Step

2-Mercapto-4-amino-5-cyano-6-arylpyrimidines (1a, b), 2-hydroxy derivatives 1c, d and 2-methylmercapto derivatives 4 a, b were synthesised via the reaction of either a mixture of malononitrile and aromatic aldehyde or arylidene malononitrile with thiourea, urea and S-methylisothiourea, respectively. 1c, d could also be obtained by the action of hydrogen peroxide on 1a, b or by the action of hydrochloric acid on 4a, b. Compounds 4a, b could also be prepared by the action of methyl iodide on 1a, b. 4a reacted with hydrazine hydrate to give the 2-hydrazino derivative 5 which condensed easily with aromatic aldehydes to give the Schiff’s bases 6 a, b. Compound 5 could be converted into the tetrazolo-and s-triazolopyrimidines 7 and 9 by the action of nitrous acid and carbon disulphide respectively. Structures of the newly synthesised compounds were established by chemical routes and spectral studies

scholarly journals Dissolution of copper from smelting slag by leaching in chloride media

2017 ◽  
Vol 53 (3) ◽  
pp. 407-412
Author(s):  
M. Dimitrijevic ◽  
D. Urosevic ◽  
S. Milic ◽  
M. Sokic ◽  
R. Markovic
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrochloric Acid ◽  
Aqueous Solutions ◽  
Room Temperature ◽  
Catalytic Decomposition ◽  
Copper Smelting ◽  
Copper Extraction ◽  
Complete Dissolution ◽  
Iron Extraction ◽  
Smelting Slag

Leaching of copper smelting slag in chloride media was studied. The lixiviants used were aqueous solutions of hydrochloric acid (0.5-2.0 M HCl) as well as hydrogen peroxide and hydrochloric acid (0.5-3.0 M H2O2, 1.0 M HCl). The maximum final copper extraction from the slag of 73% was attained with 3 M H2O2, at room temperature after 120 minutes of reaction. At the same time, 55% of the iron from the slag was also dissolved. The copper extraction increased during the first 60 minutes of reaction and essentially ceased thereafter. Because of a rapid catalytic decomposition of hydrogen peroxide, it should be added contiuously to the leach suspension rather than at once at the begining of the experiment. In fact, it appears that almost complete dissolution of copper from the slag is achievable after about 4 hours of leaching by implementing the method of continuous lixiviant addition. Also, it seems that the final iron extraction could be limitied to as low as 20% by using this method.

Nickel (II) and oxovanadium (IV) complexes supported on MCM-41 mesoporous and their application in catalytic selective sulfide and thiol oxidation

2020 ◽  
Vol 23 ◽  
Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Sol Gel ◽  
Reaction Times ◽  
Significant Loss ◽  
Spectral Studies ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Solvent Free Conditions ◽  
Mcm 41

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.

Spektralreines Bis(phthalocyaninato)protactinium(IV) / Spectroscopically Pure Bis(phthalocyaninato)protactinium(IV)

1980 ◽  
Vol 35 (5) ◽  
pp. 564-567 ◽  
Author(s):  
Franz Lux ◽  
Oskar F. Beck ◽  
Heinz Krauß ◽  
David Brown ◽  
Tze C. Tso
Keyword(s):  
Solid State ◽  
Temperature Profile ◽  
Powder Diffraction ◽  
Phthalic Acid ◽  
Room Temperature ◽  
X Ray ◽  
Derivative Spectroscopy ◽  
Solid State Spectrum

Abstract Spectroscopically pure PaPc2 has been prepared by reaction between PaI4 · 4 CH3CN and o-phthalic acid dinitrile in 1-chloronaphthalene followed by sublimation at 5 · 10-3 Pa in a temperature profile with three clearly defined zones (520 °C/350 °C/room temperature). This procedure gives a product almost completely free of H2Pc impurity which is known to have been present in previously reported complexes of the type AnPc2. Thus, the trace of H2Pc in the substance could only be detected by derivative spectroscopy. X-ray powder diffraction shows the compound to be isostructural with ThPc2 and UPc2. The ligand spectrum is typical of AnPc2 complexes, f-f Bands observed in a solid state spectrum provide additional proof that the compound is PaIV Pc2.

scholarly journals A Mn(iii) polyoxotungstate in the oxidation of organosulfur compounds by H2O2 at room temperature: an environmentally safe catalytic approach

2016 ◽  
Vol 6 (9) ◽  
pp. 3271-3278 ◽  
Author(s):  
Tiago A. G. Duarte ◽  
Sónia M. G. Pires ◽  
Isabel C. M. S. Santos ◽  
Mário M. Q. Simões ◽  
M. Graça P. M. S. Neves ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Room Temperature ◽  
Organosulfur Compounds ◽  
Keggin Type ◽  
Environmentally Safe

A manganese monosubstituted Keggin-type polyoxometalate was used as a catalyst in the oxidation of recalcitrant organosulfur compounds by hydrogen peroxide at room temperature.

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