A comparison of the efficacy of carbamazepine and the novel anti-epileptic drug levetiracetam in the tetanus toxin model of focal complex partial epilepsy
作者:Wolfgang Kirmse、Pham van Chiem、Paul-Georg Henning
DOI:10.1016/s0040-4020(01)96385-9
日期:1985.1
opylidenes (95,97) were generated from the corresponding nitrosoureas in methanol at room temperature. The diazo route is initiated by the formation of 2-vinylcyclopropanediazonium ions (e.g.43) which do not undergo 1,3-carbon shifts. No cyclopentenyl products were found in weakly basic methanol where the diazonium ions prevail. Ring opening of the diazonium ions gives pentadienyl cations and products
1-dibromo-2-vinylcyclopropane derivatives with MeLi yielded cyclopentadienes as the main products together with small amounts of allenic compounds (Table 1). By the same reaction 2,2,2′,2′-tetrabromobicyclopropyl derivatives yielded, in all but one case, only small amounts of diallenes; the exception is the exclusive formation of 2,7-dimethyl-2,3,5,6-octatetraene, (XIII) from2,2,2′,2′-tetrabromo-3,3,3′,
Photochemistry of cyclopentadiene isolated in low-temperature argon matrices
作者:Jun Miyazaki、Yasuhiro Yamada
DOI:10.1016/j.molstruc.2004.01.023
日期:2004.4
matrices was studied by means of IR and UV/VIS spectroscopy. Bicyclo[2.1.0]pent-2-ene was formed by the irradiation of matrix-isolated cyclopentadiene using a super-high-pressure mercury lamp. When the matrix-isolated cyclopentadiene was irradiated with shorter wavelength using a low-pressure mercury lamp, further reactions of bicyclo[2.1.0]pent-2-ene were found to produce allylacetylene and vinylallene.
Uses of adsorbed reagents in the synthesis of reactive molecules via elimination reactions
作者:W.E. Billups、Long-Jin Lin
DOI:10.1016/s0040-4020(01)87573-6
日期:1986.1
The synthesis of reactive molecules (in vacuo) using reagents adsorbed on inert surfaces to effect elimination reactions has been investigated. Potassium t-butoxide adsorbed on Chromosorb W can be used to generate methylenecyclopropene from 2-chloromethylenecyclopropane and 1-vinylcyclopropene from either 1,4-dichlorospiropentane or 1-chloro-2-vinylcyclopropane. Both compounds can be characterized
Dihydrothiinone 9a undergoes photocycloaddition regioselectively to all three CC bonds of penta-1,2,4-triene (10), the relative stabilities of the biradical intermediates determining the product distribution. In contrast, cyclohexenone 9b and dihydropyranone 9c afford more complex mixtures of bicyclo[4.2.0]octanones, which also turn out to be less stable on chromatographic workup, reflecting the higher