Results 171 to 180 of about 3,998 (209)
Some of the next articles are maybe not open access.
Angewandte Chemie International Edition, 2011
AbstractThe exploitation of ring strain as a driving force to facilitate chemical reactions is a well‐appreciated principle in organic chemistry. The most prominent and most frequently used compound classes in this respect are oxiranes and cyclopropanes.
Tobias, Seiser +3 more
openaire +2 more sources
AbstractThe exploitation of ring strain as a driving force to facilitate chemical reactions is a well‐appreciated principle in organic chemistry. The most prominent and most frequently used compound classes in this respect are oxiranes and cyclopropanes.
Tobias, Seiser +3 more
openaire +2 more sources
Synthesis of Cyclobutane Nucleosides
Nucleosides, Nucleotides & Nucleic Acids, 20112-(6-Chloropurinyl)-3-benzoyloxymethylcyclobutanone can be prepared by reaction of 6-chloropurine with 3-benzoyloxymethyl-2-bromocyclobutanone. The N-alkylation gave both N-9 and N-7 regioisomers. Both regioisomers upon hydride reduction followed by aminolysis gave the corresponding adenine nucleoside analogues.
Abdelaziz, Ebead +2 more
openaire +2 more sources
Neurochemical Research, 1980
Both cis- and trans-3-aminocyclobutane-1-carboxylic acid have been synthesized as conformationally restricted analogs of GABA. The cis isomer displayed weak to moderate GABA-like activity with respect to (1) inhibition of GABA uptake in rat brain minislices, (2) inhibition of sodium-independent binding of GABA to rat brain membranes, (3) activity as a ...
R D, Allan +6 more
openaire +2 more sources
Both cis- and trans-3-aminocyclobutane-1-carboxylic acid have been synthesized as conformationally restricted analogs of GABA. The cis isomer displayed weak to moderate GABA-like activity with respect to (1) inhibition of GABA uptake in rat brain minislices, (2) inhibition of sodium-independent binding of GABA to rat brain membranes, (3) activity as a ...
R D, Allan +6 more
openaire +2 more sources
Cyclobutanes from Combretum albopunctatum
Phytochemistry, 2004A dichloromethane extract of the aerial parts of Combretum albopunctatum Suesseng afforded five phenolic compounds-three known flavonoids and two novel cyclobutane chalcone dimers. The chemical structures were determined by standard spectroscopic techniques and the structure and relative stereochemistry of one chalcone dimer, rel-(1 alpha,2 beta)-di-(2,
Katerere, D.R. +4 more
openaire +3 more sources
Infrared and Raman spectra of cyclobutane and cyclobutane-d8
Spectrochimica Acta Part A: Molecular Spectroscopy, 1972Abstract New i.r. and Raman measurements are reported for cyclo butane and cyclo butane- d 8 . They include i.r. spectra on the gas at room temperature and on the solid at about 100°K. Raman spectra have been measured for the gas and liquid at room temperature and for the solid at 113°K. These data allow the assignments (for D 2d ) to be put on
Foil A. Miller +3 more
openaire +1 more source
Cycloreversion of cyclobutanes
Theoretica Chimica Acta, 1980Semiempirical MO calculations with the method SINDO1 were performed to study the potential energy surface of cyclobutane and several substituted cyclobutanes with substituents F, OCH3 and CN. The reaction pathway with the lowest activation energy leading to two ethylenic fragments is nonconcerted.
Karl Jug, Peter L. Müller
openaire +1 more source
Tetrahedron, 1967
Abstract NMR spectra and basic equilibration of cis and trans methyl-3-isopropylcyclobutanecarboxylate are reported. Treatment of the nonplanar cyclobutane system by analogy with cyclohexane is potentially possible, but limited by (1) greater dependence of ring puckering on substituents; and (2) intervention of planar conformers.
I. Lillien, R.A. Doughty
openaire +1 more source
Abstract NMR spectra and basic equilibration of cis and trans methyl-3-isopropylcyclobutanecarboxylate are reported. Treatment of the nonplanar cyclobutane system by analogy with cyclohexane is potentially possible, but limited by (1) greater dependence of ring puckering on substituents; and (2) intervention of planar conformers.
I. Lillien, R.A. Doughty
openaire +1 more source
Bioactive cyclobutane-containing alkaloids
Journal of Natural Medicines, 2007The present review describes research on novel natural cyclobutane-containing alkaloids and synthetic compounds isolated from terrestrial and marine species. More than 210 compounds have been confirmed to show antimicrobial, antibacterial, anticancer, and other activities.
openaire +2 more sources
Tetrahedron, 1974
Abstract The literature concerning the structures of compounds containing saturated, 4-carbon rings is reviewed critically, and the variety of conformations (dihedral angles of 0° to 30° ± 6°) of the cyclobutane ring are tabulated and discussed.
F.Albert Cotton, Bertram A. Frenz
openaire +1 more source
Abstract The literature concerning the structures of compounds containing saturated, 4-carbon rings is reviewed critically, and the variety of conformations (dihedral angles of 0° to 30° ± 6°) of the cyclobutane ring are tabulated and discussed.
F.Albert Cotton, Bertram A. Frenz
openaire +1 more source
Cyclobutan‐tetracarbonsäuren‐(1.2.3.4)
Chemische Berichte, 1960AbstractDurch Ozonabbau von Truxillsäuren konnten 3 der 4 möglichen Cyclobutantetracarbonsäuren‐(1.2.3.4) hergestellt werden.
Rudolf Criegee, Hermann Höver
openaire +1 more source