Zobrazeno 1 - 10
of 60
pro vyhledávání: '"D. M. Brouwer"'
Autor:
D. M. Brouwer
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 88:530-544
A PMR spectroscopic study has been made of the protonation of 1-hexen-5-one (I), 2-methyl-l-hexen-5-one (II), 2-hepten-6-one (III) and 2-methyl-2-hepten-6-one (IV) in different acids (HF, HF-SbF5, H2SO4, FSO3H, FSO3H-SbF5). With two exceptions, the f
Autor:
D. M. Brouwer
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 87:611-622
Rate constants and activation parameters of the following methylbenzenium ion rearrangements have been determined by direct measurement in HF containing SbF5: o-xylenium and p-xylenium to m-xylenium, 1,2,3,4- to 1,2,3,5-tetramethylbenzenium, 1,2,3- t
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 91:1359-1363
The rearrangement of 2,5,5- to 2,4,5-trimethyldihydrofuryl ion, a heteroaromatic rearrangement via 1,2-methyl and hydride shifts, is reported. The half-life of the reaction is about 25 minutes at 100°.
Autor:
J. A. Van Doorn, D. M. Brouwer
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 88:1041-1057
Proton magnetic resonance spectra of a number of simple alkenesulfonic acids and related hydroxyalkanesulfonic acids have been measured. The compound described in the literature as 2-methylpropene-1,3-disulfonic acid (I) has been found to be 2-methyl
Autor:
D. M. Brouwer, J. A. Van Doorn
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 89:88-96
Protonation of 9-ethyl-10-methylanthracene in HF or CF3COOH/H2O · BF3 affords a mixture of the 9H+- and 10H+-9-ethyl-10-methylanthracenium ions. These ions differ in free energy by only 0.9-1.0 kcal · mole−1. This small difference in stability, w
Autor:
D. M. Brouwer
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 88:9-12
Autor:
J. A. Van Doorn, D. M. Brouwer
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 89:333-352
A detailed investigation has been made of the reversible rearrangement of the 1,2,3,4,5-pentamethylcyclopentenyl ion (1) to the 1,2,3,4,4-pentamethylcyclopentenyl ion (3). In 5: 1 FSO3H-SbF5 this reaction proceeds entirely intramolecularly by 1,2-hyd
Autor:
D. M. Brouwer
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 87:335-341
2-Fluoro-, chloro- and bromomesitylenes, and 5-fluoro-, chloro- and bromo-m-xylenes have been found to form stable benzenium ions in HF-SbF5. The cations give well-resolved PMR spectra, from which their structures have been derived. The 2-halomesityl
Autor:
D. M. Brouwer, J. A. Van Doorn
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 90:535-548
Publikováno v:
Recueil des Travaux Chimiques des Pays-Bas. 94:198-203
The cyclization of hydroxyallyl ions (protonated 3-alken-2-ones) to tetrahydrofuryl ions in a series of strong acids (HF, H2SO4, FSO3H) and superacids (FSO3HSbF5, HFSbF5) has been studied, together with some related reactions. The rates of cyclizatio