126,388 research outputs found
Beckmann rearrangement of α-oximinoketones
No full text963-965The Beckmann rearrangement of α-oximinoketones gives benzoic acids as chief isolable products. Both first order and second order Beckmann rearrangements have been observed. The occurrence of first order Beckmann rearrangement in these oximinocarbonyl compounds is confirmed through the identification of the products obtained
Beckmann Rearrangement of Ketoxime Catalyzed by N-methyl-imidazolium Hydrosulfate
No full textBeckmann rearrangement of ketoxime catalyzed by acidic ionic liquid-N-methyl-imidazolium hydrosulfate was studied. Rearrangement of benzophenone oxime gave the desirable product with 45% yield at 90 °C. When co-catalyst P2O5 was added, the yield could be improved to 91%. The catalyst could be reused three cycles with the same efficiency. Finally, reactions of other ketoximes were also investigated
One-Pot Synthesis of <i>N</i>-Imidoylbenzotriazoles via Benzotriazole-Mediated Beckmann Rearrangement of Oximes
No full textN-Imidoylbenzotriazoles 5a−l are obtained under mild conditions in variable yields (20−87%) by reactions of oximes 2a−l with BtTs 1 via a
Beckmann rearrangement
Beckmann Transformation of 2,5,6-Trimethoxyindan-1-one Oxime
No full textThe title compound on Beckmann transformation is cleaved to 2-cyano-4,5-dimethoxyphenylacetaldehyde
Beckmann, Marcelli (Death, 1903-07-21)
No full textAddress: 32 Vine St.Age at death: 11 Mo.Pg 76/1903/432/FW S/City/Dr. N. W. Abbott/A. H. Moorman/St. Joseph's OldOriginal record filed in drawer labeled 'BECKMANN-BIERLE'
Les premiers vers du Cligès
No full textBeckmann Gustav Adolf. Les premiers vers du Cligès. In: Romania, tome 122 n°485-486, 2004. pp. 202-205
Max Beckmann, un artiste face à la barbarie
No full textBlœss Georges. Max Beckmann, un artiste face à la barbarie. In: Chimères. Revue des schizoanalyses, N°51, automne 2003. pp. 128-143
Structure-reactivity correlations of the abnormal Beckmann reaction of dihydrolevoglucosenone oxime
No full textA structural, spectroscopic and computational study of a series of oximes was undertaken to investigate how geometric and structural changes relevant to the reaction coordinate for the Beckmann reaction (normal Beckmann) and Beckmann fragmentation (abnormal Beckmann) manifest in the ground state. X-ray structures of a range of oximes derived from dihydrolevoglucosan (Cyrene™; which undergoes the abnormal Beckmann reaction), in which the oxygen substituent was systematically varied were determined. As the electron demand of the OR group increased, the major structural changes included lengthening of the N-OR bond distance, and a decrease in the magnitude of the C2[double bond, length as m-dash]N-O bond angle, consistent with the changes seen for cyclohexanone oximes, which undergo the normal Beckmann reaction. However, unique to the Cyrene oximes, an increase in the length of the fissile C1-C2 bond was observed, which correlated with a decrease in the 13C-13C 1-bond coupling constants as the electron demand of the OR substituent increased. Computational studies of Cyrene and cyclohexanone oximes using Natural Bond Orbital analysis support an electronic structure involving n(O) → σ*C1-C2 and σC1-C2 → σ*N-O localized orbital interactions
Franz Beckmann. Geographie und Ethnographie in Caesars «Bellum Gallicum »
No full textFranz Beckmann. Geographie und Ethnographie in Caesars «Bellum Gallicum ». In: Supplément critique au Bulletin de l'Association Guillaume Budé, n°3,1931. pp. 152-155
P. J. Th. Beckmann, Das Gebet bei Homer, 1932
No full textMathieu Georges. P. J. Th. Beckmann, Das Gebet bei Homer, 1932. In: Revue des Études Anciennes. Tome 35, 1933, n°1. p. 96
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