?,?-unsaturated ketones in substitutive addition with 2-alkylfurans and some transformations of the reaction products

1981 ◽  
Vol 17 (12) ◽  
pp. 1158-1161 ◽  
Author(s):  
Sh. T. Akhmedov ◽  
N. S. Sadykhov ◽  
R. Sh. Akhmedova ◽  
N. S. Zefirov
Keyword(s):  
Reaction Products ◽  
Unsaturated Ketones ◽  
Substitutive Addition

On the Stereoselectivity of the (-)-Dimenthyl Malonate Addition to α,β-Unsaturated Ketones

1996 ◽  
Vol 61 (12) ◽  
pp. 1805-1814 ◽  
Author(s):  
Ľubomír Šebo ◽  
Juraj Alföldi ◽  
Grety Rihs ◽  
Štefan Toma
Keyword(s):  
Michael Addition ◽  
Pure State ◽  
Nmr Spectra ◽  
Reaction Products ◽  
X Ray ◽  
Unsaturated Ketones ◽  
H Nmr ◽  
The Michael Addition

The Michael addition of (-)-dimenthyl malonate to eight α,β-unsaturated ketones has been studied. The ratio of diastereomers was calculated on the basis of the 1H NMR spectra of the crude reaction products. The diastereomer excess varied from 10 to 50%, depending on the structure of the starting enone. The pure diastereomer produced by addition of (-)-dimenthyl malonate to 2-benzylidene-1,4-indandione was isolated by repeated crystallization. X-ray analysis has shown that the isomer is (-)-dimenthyl (R)-2-[1-(1,3-dioxoindan-2-yl)-1-phenylmethyl]malonate (5a). The predominating diastereomers of (-)-dimenthyl(3-ferrocenyl-3-oxophenylpropyl)malonate (1a) and (-)-dimenthyl-2-(1-(1,3-dioxo[3]ferrocenophan-2-yl)-1-phenyl malonate (6a) were also isolated in pure state by careful crystallization.

Methods for preparation of heterobifunctional nitroxides: α,β-unsaturated ketones, β-ketoesters, cyano-nitro-derivatives

1982 ◽  
Vol 60 (12) ◽  
pp. 1432-1438 ◽  
Author(s):  
H. Olga Hankovszky ◽  
Kálmán Hideg ◽  
László Lex ◽  
Gyula Kulcsár ◽  
H. Anna Halász
Keyword(s):  
Methyl Ketones ◽  
Reaction Products ◽  
Unsaturated Ketones ◽  
Nitro Derivatives

The reactions of 1-oxyl-2,2,5,5-tetramethyl-3-pyrroline-3-carboxaldehyde (1), 1-oxyl-2,2,5,5-tetramethyl-3-cyano-3-pyrroline (2), ethyl 1-oxy(-2,2,5,5-tetramethyl-3-pyrroline-3-carbonyl carbonate (3), and N-(1-oxyl-2,2,5,5-tetramethyl-3-pyrroline-3-carbonyl)imidazolide (4) are investigated with several nucleophiles (dialkylcadmium, diethyl sodio-malonate, magnesium enolate of ethyl hydrogen malonate, nitromethane-anion) to obtain α,β-unsaturated ketones, β-ketoesters, or conjugated reaction products. Aldehyde 1 is reacted with several methyl ketones (acetylmethylene-triphenylphosphorane, acetophenone, 2-acetylpyridine, 4-phenyl-3-butyn-2-one) to give spin labeled polyenones. The reaction of 4-(1-oxyl-2,2,5,5-tetramethyl-3-pyrroline-3-yl)-2-buten-2-one (24a) with ethylenediamine gives 7,14-bis-(1-oxyl-2,2,5,5-tetramethyl-3-pyrroline-3-yl)-5,12-dimethyl-1,4,8,11-tetraazatetradeca-7,14-diene biradical (25).

Reactions of dodecacarbonyltriruthenium with ?,?-unsaturated ketones. Crystal and molecular structures of two reaction products

1993 ◽  
Vol 42 (7) ◽  
pp. 1228-1235 ◽  
Author(s):  
L. V. Rybin ◽  
S. V. Osintseva ◽  
A. S. Batsanov ◽  
Yu. T. Struchkov ◽  
P. V. Petrovskii ◽  
...  
Keyword(s):  
Molecular Structures ◽  
Reaction Products ◽  
Unsaturated Ketones ◽  
Crystal And Molecular Structures

Reactions of α,β-unsaturated ketones with arylacetonitriles

1987 ◽  
Vol 52 (4) ◽  
pp. 1021-1025 ◽  
Author(s):  
Mohammad M. Al-Arab ◽  
Ali M. Issa
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Room Temperature ◽  
Sodium Ethoxide ◽  
Reaction Products ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Unsaturated Ketones ◽  
Single Diastereomer ◽  
Lanthanide Shift Reagents ◽  
Diastereomeric Purity

1,3-Diaryl-2-propene-1-ones I react with arylacetonitriles II in the presence of sodium ethoxide at room temperature to give a single diastereomer of the corresponding 2,3-diaryl-4-aroylbutyronitriles III. The structures of the reaction products were established by infrared, nuclear magnetic resonance, and mass spectral data as well as elemental analysis. The diastereomeric purity was determined by NMR measurements using lanthanide shift reagents. The observed resonances did not show any resolved diastereomeric proton signals.

Lead aspartate: a new en bloc stain for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 34-35
Author(s):  
J.R. Walton
Keyword(s):  
Electron Microscopy ◽  
Calcium Ion ◽  
Enzyme Reaction ◽  
Lead Citrate ◽  
Reaction Products ◽  
En Bloc ◽  
Thin Sections ◽  
Lead Salts ◽  
Thin Sectioning ◽  
High Alkalinity

In electron microscopy, lead is the metal most widely used for enhancing specimen contrast. Lead citrate requires a pH of 12 to stain thin sections of epoxy-embedded material rapidly and intensively. However, this high alkalinity tends to leach out enzyme reaction products, making lead citrate unsuitable for many cytochemical studies. Substitution of the chelator aspartate for citrate allows staining to be carried out at pH 6 or 7 without apparent effect on cytochemical products. Moreover, due to the low, controlled level of free lead ions, contamination-free staining can be carried out en bloc, prior to dehydration and embedding. En bloc use of lead aspartate permits the grid-staining step to be bypassed, allowing samples to be examined immediately after thin-sectioning.Procedures. To prevent precipitation of lead salts, double- or glass-distilled H20 used in the stain and rinses should be boiled to drive off carbon dioxide and glassware should be carefully rinsed to remove any persisting traces of calcium ion.

Studies of Oxide Formation on Copper Thin Films by Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 316-317
Author(s):  
G. G. Hembree ◽  
M. A. Otooni ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Crystal Surface ◽  
Crystal Defects ◽  
Diffraction Reflection ◽  
Reaction Products ◽  
Intermediate Energies ◽  
Crystal Films ◽  
Reflection Electron Microscopy

The formation of oxide structures on single crystal films of metals has been investigated using the REMEDIE system (for Reflection Electron Microscopy and Electron Diffraction at Intermediate Energies) (1). Using this instrument scanning images can be obtained with a 5 to 15keV incident electron beam by collecting either secondary or diffracted electrons from the crystal surface (2). It is particularly suited to studies of the present sort where the surface reactions are strongly related to surface morphology and crystal defects and the growth of reaction products is inhomogeneous and not adequately described in terms of a single parameter. Observation of the samples has also been made by reflection electron diffraction, reflection electron microscopy and replication techniques in a JEM-100B electron microscope.A thin single crystal film of copper, epitaxially grown on NaCl of (100) orientation, was repositioned on a large copper single crystal of (111) orientation.

Precipitation in silicon: Microanalysis

1988 ◽  
Vol 46 ◽  
pp. 474-475
Author(s):  
R.W. Carpenter
Keyword(s):  
Transition Metals ◽  
Spatial Resolution ◽  
Thin Foil ◽  
Precipitation Reaction ◽  
High Current ◽  
Reaction Products ◽  
Carbon And Nitrogen ◽  
Dielectric Layers ◽  
Precipitation Processes ◽  
Areas Of Interest

Interest in precipitation processes in silicon appears to be centered on transition metals (for intrinsic and extrinsic gettering), and oxygen and carbon in thermally aged materials, and on oxygen, carbon, and nitrogen in ion implanted materials to form buried dielectric layers. A steadily increasing number of applications of microanalysis to these problems are appearing. but still far less than the number of imaging/diffraction investigations. Microanalysis applications appear to be paced by instrumentation development. The precipitation reaction products are small and the presence of carbon is often an important consideration. Small high current probes are important and cryogenic specimen holders are required for consistent suppression of contamination buildup on specimen areas of interest. Focussed probes useful for microanalysis should be in the range of 0.1 to 1nA, and estimates of spatial resolution to be expected for thin foil specimens can be made from the curves shown in Fig. 1.

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