Nitrones and oxazirans. III. Photolysis of 1-pyrroline 1-oxides and their related oxazirans

1968 ◽  
Vol 21 (10) ◽  
pp. 2507 ◽  
Author(s):  
JB Bapat ◽  
DS Black
Keyword(s):  
Trans Isomer ◽  
Trans Isomers ◽  
Perbenzoic Acid ◽  
Stereo Selectivity ◽  
Cis And Trans

Oxazirans have been prepared from a number of 1-pyrroline 1-oxides by photoisomerization and from the related 1-pyrrolines by oxidation with perbenzoic acid. This oxidation was found to be highly stereoselective in reaction with unsymmetrical pyrrolines, and 3,5-cis-disubstituted oxazirans were formed exclusively. A mixture of 3,5-cis- and trans-disubstituted oxazirans was formed in the photolysis of unsymmetrical 2-methyl-substituted pyrroline 1-oxides but stereo-selectivity was observed in the photolysis of similar 2-aryl-substituted pyrroline 1-oxides, in which cases only the trans-isomer was obtained. Photoisomerization of cis-5-phenyl-substituted oxazirans to their trans-isomers was also observed, while other oxazirans were found to be photo-stable.

SYNTHESES IN THE TERPENE SERIES: VIII. SYNTHESIS OF THE CIS- AND TRANS-ISOMERS OF 7,7,10-TRIMETHYLDECAL-1-ONE. A CONVENIENT MODIFICATION OF THE BROWN HYDRATION REACTION

1959 ◽  
Vol 37 (11) ◽  
pp. 1870-1880 ◽  
Author(s):  
Franz Sondheimer ◽  
Saul Wolfe
Keyword(s):  
Trans Isomer ◽  
Raney Nickel ◽  
Equilibrium Mixture ◽  
Hydration Reaction ◽  
Trans Isomers ◽  
Perbenzoic Acid ◽  
Cis And Trans Isomers ◽  
Cis And Trans

7,7,10-Trimethyl-Δ1(9)-octal-2-one (VII) was converted to the cycloethylenedithioketal (VIII), which on Raney nickel reduction yielded 7,7,10-trimethyl-Δ1(9)-octalin (IX). Oxidation with perbenzoic acid led to the corresponding oxide (X), which could be rearranged in low yield to an equilibrium mixture of 7,7,10-trimethyldecal-1-one consisting essentially of the trans-isomer (XI).A convenient modification of the Brown hydration reaction is described, whereby the necessity of generating diborane or of using diglyme is avoided. 7,7,10-Trimethyl-Δ1(9)-octalin (IX) on Brown hydration using this modification stereospecifically furnished 7,7,10β-tri-methyl-cis-decal-1β-ol (XII), which was oxidized to 7,7,10-trimethyl-cis-decal-1-one (XIII). Isomerization resulted in the above-described equilibrium mixture containing at least 90% of the trans-isomer (XI). Similarly, the previously described 10-methyl-Δ1(9)-octalin (XVI) yielded a mixture of the cis- and trans-isomers of 10-methyldecal-1-one (XIX). Syntheses of 2-methylene-7,7,10-trimethyl-Δ1(9)-octalin (XIV) and of 7,7,10-trimethyl-cis-decal-2,3-dione 3-dithiotrimethylene ketal (XXII) are also described.

Sur la réduction de polyméthyldihydro-2,3 phénalènones-1 par l'hydrure de lithium et d'aluminium

1974 ◽  
Vol 52 (17) ◽  
pp. 3106-3112 ◽  
Author(s):  
E. Costakis ◽  
P. Canonne ◽  
R. St-Jean
Keyword(s):  
Trans Isomer ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Considerable Extent ◽  
Lithium Aluminum ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Cis Isomer ◽  
Steric Constraints

The reduction of some polymethyl-2,3-dihydro phenalen-1-ones by lithium aluminum hydride yields a mixture of cis and trans isomers; the percentage of each isomer depends to a considerable extent on its structure. Indeed, for some, the trans isomer predominates while for others the cis isomer is obtained in up to 88% yields. Moreover, in the particular case in which the trans isomer is formed in low yields, its preferred conformation is trans diaxial.The steric constraints which render certain transition states unfavourable during the attack of the hydride are discussed with the aid of spectroscopic data on the alcohols obtained. [Journal translation]

Synthesis and study of Pt(II)–nitrile complexes. Multinuclear NMR spectra and crystal structures of compounds of the types [Pt(R-CN)Cl3]− and cis and trans-Pt(R-CN)2Cl2

1996 ◽  
Vol 74 (2) ◽  
pp. 144-152 ◽  
Author(s):  
Fernande D. Rochon ◽  
Robert Melanson ◽  
Eryk Thouin ◽  
Corinne Bensimon ◽  
André L. Beauchamp
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Trans Isomer ◽  
Nmr Spectra ◽  
Alkyl Chain ◽  
Coupling Constants ◽  
Trans Isomers ◽  
Multinuclear Nmr ◽  
Cis And Trans ◽  
Bond Trans

Complexes of the type [Pt(R-CN)Cl3]− were synthesized and studied by 1H, 13C, and 195Pt NMR spectroscopies. The 2J(195Pt-13C) coupling constants are about 240 Hz. The signals due to the cyano carbon atoms of the coordinated ligands were observed at higher fields than those of the free ligands. The shielding on the cyano carbon increases as the alkyl chain lengthens and also when the branching increases. The 195Pt signals of all the complexes were observed around −2000 ppm. The crystal structures of (NMe4)[Pt(C3H7-CN)Cl3] (1) and (NMe4)[Pt(p-HO-C6H4-CN)Cl3] (2) were determined. Compound 1 is monoclinic, P21/c, a = 8.384(5), b = 15.336(19), c = 11.759(9) Å, β = 99.52(6)°, Z = 4, R = 0.054, and wR = 0.051. Crystal 2 is tetragonal with a = 16.222(6), c = 12.052(5) Å, Z = 8, R = 0.059, and wR = 0.044. The Pt—CL bond trans to the nitrile ligand is shorter than normal (2.276(3) Å for 1 and 2.264(7) Å for 2) while the two other bonds are normal (2.293(4), 2.287(3) Å for 1 and 2.320(7), 2.275(8) Å for 2). The Pt—N bonds are 1.97(1) Å (1) and 1.92(2) Å (2) and the segments Pt-N≡C-C are linear. Disubstituted compounds were also synthesized and studied by multinuclear NMR. The 195Pt signals of the cis isomers were observed at lower fields than those of the trans isomers (Δ ≈ 65 ppm), while the 13C signals of the cyano carbons of the trans isomers were observed at lower fields than those of the cis compounds (Δ ≈ 0.6 ppm). The cis complexes isomerize to the trans compounds upon heating. The crystal structures of cis-(3) and trans-Pt(C2H5-CN)2Cl2 (4) and also of cis-Pt(p-HO-C6H4-CN)2Cl2 (5) were determined. Crystal 3 is monoclinic, P21/c, a = 7.506(5), b = 9.539(5), c = 14.823(7) Å, β = 92.31(4)°, Z = 4, R = 0.050, and wR = 0.042. The trans isomer 4 is monoclinic with the Pt atom on an inversion centre, P21/c, a = 5.149(4), b = 9.394(8), c = 10.944(10) Å, β = 97.84(7)°, Z = 4, R = 0.017 and wR = 0.020. Finally, compound 5 is triclinic, P-1, a = 7.464(3), b = 10.712(6), c = 12.291(5) Å, α = 75.63(4)°, β = 75.63(4)°, γ = 80.32(4)°, Z = 2, R = 0.045, and wR = 0.056. The Pt—Cl bond distances for the cis isomers are 2.269(5), 2.270(4) Å for 3 and 2.274(2), 2.279(3) Å for 5 while they are 2.289(3) Å for the trans isomer (4). The Pt—N bonds are 1.962(14), 1.988(11) Å (3), 1.972(7), 1.976(7) Å (5) and 1.969(5) Å for 4. Key words: platinum, nitrile, NMR, isomerization, crystal structure.

Reactions of Alkynes with Dicarbonyl(η-cyclopentadienyl)iridium

1979 ◽  
Vol 32 (10) ◽  
pp. 2147 ◽  
Author(s):  
PA Corrigan ◽  
RS Dickson
Keyword(s):  
Trans Isomer ◽  
Spectroscopic Data ◽  
Spectroscopic Properties ◽  
Organometallic Complexes ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
Related Reaction ◽  
Cis Isomer

Six organometallic complexes have been isolated from the reaction between (η-C5H5)Ir(C0)2 and hexafluorobut-2-yne at 120-160�. Both the cis and trans isomers of the σ-bridging alkyne complex (η C5H5)2Ir2(CO)2(CF3C2CF3) were obtained; the cis isomer is slowly transformed to the trans isomer at 160�. These complexes do not react further with alkynes. Two other products were identified as an iridiocyclobutenone complex and a iridiocyclopentadiene complex, viz.(η-C5H5){IrC(CF3)=C(CF3)CO}(CO) and (η-C5H5){IrC(CF3)=C(CF3)C(CF3)}(CO)These complexes are also inert to further reaction with hexafluorobut-2-yne, and the iridiocyclopentadiene complex could not be converted into the cyclopentadienone complex (η-C5H5)Ir{C4(CF3)4-CO). The spectroscopic properties of a product of formula (η-C5H5)Ir(CF3C2CF3)2(C4HF5) indicate it incorporates a 1-(2',2'-difluoroethenyl)-1,2,3,4,5-pentakis(trifluoromethyl)cyclopenta-2,4-diene ligand. The final product was formulated as (η-C5H5)Ir2(CO)3(CF3C2CF3)2H and five alternativestructures are consistent with the spectroscopic data. The related reaction between (η-C5H5)Ir(CO)2 and but-2-yne at 180� gives a small amount of hexamethylbenzene plus the maleoyl complex(η-C5H5){IrC(O)(Me=C(Me)C(O)}(CO).

Selective Supramolecular Membrane Transport of cis and trans Diastereoisomers of the Diamminebis(ethane-1,2-diamine)cobalt(III) Cation by the Natural Ionophore Lasalocid A

1995 ◽  
Vol 48 (4) ◽  
pp. 879 ◽  
Author(s):  
PSK Chia ◽  
AJ Leong ◽  
LF Lindoy ◽  
GW Walker
Keyword(s):  
Membrane Transport ◽  
Trans Isomer ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Carrier Mediated Transport ◽  
Significant Difference ◽  
Transport Experiment ◽  
Transport Behaviour ◽  
Source Phase ◽  
Cis And Trans

Carrier-mediated transport of the cis and trans diastereoisomers of the diamminebis (ethane-1,2-diamine)cobalt(III) cation across a chloroform membrane by the natural ionophore lasalocid A is reported. In the case where individual isomers were run, no significant difference in their transport behaviour was observed. However, a competitive transport experiment in which equimolar concentrations of the cis and trans isomers of the above cation were present in the source phase led to enhanced transport of the trans isomer relative to the cis. Under the conditions employed, the final cis-to-trans ratio in the receiving phase was 1 : 3.

Photochemical and thermal isomerizations of cis- and trans-cinnamic acids, and their photostationary state

1969 ◽  
Vol 47 (24) ◽  
pp. 4567-4576 ◽  
Author(s):  
Martin B. Hocking
Keyword(s):  
Trans Isomer ◽  
Cinnamic Acid ◽  
Thermal Equilibrium ◽  
Vacuum Distillation ◽  
Trans Isomers ◽  
Cinnamic Acids ◽  
Concentrated Solutions ◽  
Photostationary State ◽  
Kinetic Expression ◽  
Cis And Trans

cis-Cinnamic acid was prepared photochemically from the trans isomer according to a published method, but was isolated by vacuum distillation. The photostationary state of these acids has been determined for moderately concentrated solutions of each isomer exposed to unfiltered ultraviolet. The position of the cis–trans thermal equilibrium approached from all cis- and from all trans-isomers has been tested without solvent and found to lie at, or very close to, 100% trans. Kinetic examination of the rates of these isomerizations shows that they fit a kinetic expression of the form −d[cis]/dt = k[cis] [H+].

Polarography of some coordination compounds of Platinum. III. Ions of the tetrammineplatinum(II) type

1956 ◽  
Vol 9 (1) ◽  
pp. 14 ◽  
Author(s):  
JR Hall ◽  
RA Plowman
Keyword(s):  
Trans Isomer ◽  
Coordination Compounds ◽  
Supporting Electrolyte ◽  
Mercury Electrode ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Current Voltage ◽  
Dropping Mercury Electrode ◽  
Divalent Platinum ◽  
Cis And Trans

A number of tetrammine ions of divalent platinum, in which the ligands were ammonia, methylamine, dimethylamine, ethylenediamine, pyridine, aniline, and combinations of some of these, were studied at the dropping mercury electrode. Some of the ions showed maxima in their current-voltage curves (c-v curves). The formation of hydrogen interfered with the c-v curves of other ions, so that limiting currents were not obtainable. A method was devised for the measurement of a voltage by means of which the ease of reduction of the ions could be compared. Using a supporting electrolyte of 0.1M KCl and 0.01% gelatin, the order of increasing ease of reduction was found to be [Pt{(CH3)2NH)4]2+ = [Pt(NH3)4]2+ = [Pt(NH3)3(C5H5N)]2+ = [Pt{C2H4(NH2)2}2]2+ < cis-[Pt(NH3)2(C5H5N)2]2+ < trans-[Pt(NH3)2C5H5N)2]2+ < [Pt(CH3NH2)4]2+ = [Pt(NH3)(C5H5N)3]2+ <[Pt(C6H5N)4]2+ < cis-[Pt(NH3)2(C6H5NH2)2]2+ < trans-[Pt(NH3)2(C6H5NH2)2]2+. When the ammonia groups of [Pt(NHS),l2+ were successively replaced by pyridine groups, the resulting e-v curves shifted progressively to more positive voltages. It was also found that cis- and trans-isomers of [PtA,B,I2+ reduced at different voltages. The trans-isomer reduced more readily.

Synthesis and NMR characterization of the cis and trans isomers of [Ptii(N9-adeH)2(pz)2] and X-ray crystallography of the trans isomer

2007 ◽  
pp. 3966 ◽  
Author(s):  
Karel D. Klika ◽  
Henri Kivelä ◽  
Vladimir V. Ovcharenko ◽  
Ville Nieminen ◽  
Reijo Sillanpää ◽  
...  
Keyword(s):  
Trans Isomer ◽  
Trans Isomers ◽  
X Ray ◽  
X Ray Crystallography ◽  
Cis And Trans Isomers ◽  
Nmr Characterization ◽  
Cis And Trans

scholarly journals Proton Magnetic Resonance Analysis of the trans Isomer of 2-Chloro-4-methyl-1,3,2-dioxaphospholane and the cis and trans Isomers of 2-Chloro-4,5-dimethyl-1,3,2-dioxaphospholane.

1972 ◽  
Vol 26 ◽  
pp. 2153-2156 ◽  
Author(s):  
Knut Bergesen ◽  
Trond Vikane ◽  
Thor Gramstad ◽  
Olof Wennerström ◽  
Sigfrid Svensson
Keyword(s):  
Magnetic Resonance ◽  
Trans Isomer ◽  
Proton Magnetic Resonance ◽  
Trans Isomers ◽  
Resonance Analysis ◽  
Cis And Trans Isomers ◽  
Cis And Trans

Gas Chromatographic Analysis of Insect Attractants: Trimedlure, Medlure, Siglure, Butyl Sorbate, Cue-lure, Methyleugenol

1964 ◽  
Vol 47 (5) ◽  
pp. 838-841
Author(s):  
Morton Beroza ◽  
Rafael Sarmiento
Keyword(s):  
Gas Chromatography ◽  
Trans Isomer ◽  
Chromatographic Analysis ◽  
Insect Pests ◽  
Sharp Peak ◽  
Single Peak ◽  
Trans Isomers ◽  
High Quality ◽  
Cis And Trans Isomers ◽  
Cis And Trans

Abstract Means of analyzing trimedlure, medlure, siglure, butyl sorbate, cue-lure, and methyleugenol by gas chromatography have been devised to ensure the procurement of high quality attractants needed for the detection of insect pests, especially those invading noninfested areas. The methods permit the estimation of the 4 trans isomers present in commercially produced trimedlure and medlure, and of the cis and trans isomers of siglure. Commercially available butyl sorbate gives a single sharp peak and is supposed to be the trans, trans isomer. Cue-lure and methyleugenol each give a single peak.

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