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1.
The transannular cycloaddition between the double bond on the side chain and the -benzoquinone ring in -C8-bridged -benzo-quinones by way of an oxyallyl intermediate is described. 相似文献
2.
The nitration of -cresol by nitric acid in aqueous sulphuric acid involves ~40% -substitution at CMe. The 4-methyl-4-nitrocyclohexa-2,5-dien-1-one (I) formed undergoes an acid-catalysed rearrangement to 4-methyl-2-nitrophenol. 相似文献
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The cycloaddition of the dispiro compound, , with a variety of 1,3-butadienes affords diacetates of -C8-bridged hydroquinones, which are led to the corresponding hydroquinones and -benzoquinones. 相似文献
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Diastereoisomers of 1,4-dimethyl-4-nitro-2,5-cyclohexadienyl acetate exchanged acetoxyls for alkoxyls on irradiation in alcohols to give the diastereoisomers of alkyl, 1,4-dimethyl-4-nitro-2,5-cyclohexadienyl ethers in isomer ratios of 70:30, whereas the irradiation in pentane yielded -xylene. 相似文献
5.
Nmr and UV studies show that -dimethylamino--bromostyrene, I, undergoes SNl reaction in H2O and HClO4 (kSNl = 6 × 10?1sec.?1 at 25°). The vinyl cation has an extraordinary selectivity for capture by aromatic amines relative to H2O, including I itself to give the dimer II. 相似文献
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The Diels-Alder reaction of -benzoquinone with substituted dienoic esters affords good yields of 4a,5,8,a-tetrahydro-1,4-naphthalenediones, free from the isomeric hydroquinone. The reactions were conducted at room temperature under 15 kbar (1.5 GPa) pressure in dichloromethane solutions. 相似文献
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Monomeric -dimethylamino--bromostyrene undergoes SNl increasingly slowly in 60 to 91% dioxane. Reaction is catalyzed by HClO4, NaOH and NaClO4. Dimer 11 reverts to monomer I in 91% dioxane. There is only a small solvent effect on the solvolysis rate of II. 相似文献
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Superoxo Co(III) complexes derived from Co(Salpr) and [Co(CN)5]3? reacted with 2,6-di--butyl--benzoquinone methides to give 2,6-di--butyl--benzoquinone and 2,6-di--butyl-2,5-cyclohexadienonespirooxiranes as the main products, which are considered to result from nucleophilic attack by the superoxo species on the exo double bond of the quinone methides. 相似文献
13.
Rudolph A. Abramovitch Suchet S. Mathur Daniel W. Saunders Danny P. Vanderpool 《Tetrahedron letters》1980,21(8):705-708
Pyridinium -toluenesulfonylmethylide serves as a formyl anion equivalent and, in the presence of an alcohol, undergoes 1,4-addition to -substituted maleimides to give alkoxy- (or aryloxy)-methylene-succinimides. The protected aldehyde group can be liberated readily. 相似文献
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J Leitich 《Tetrahedron letters》1980,21(32):3025-3028
The relative rates of formation of and [2+2]cycloadducts of benzyne to , - and , -1,5-cyclooctadiene, - and -cyclooctene are discussed and properties of the adducts (e.g., their unusual hydrogenation) are described. 相似文献
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All four isomers of substituted 3-alkylthio-4-hydroxybutenes have been synthesised: both the geometry of the double bond and the relative stereochemistry of the two chiral centres are controlled. 相似文献
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Photolysis of -butyl azide in N2 matrices at 12 K gives the imine 3a; matrix IR spectra for imines 4a and 5a are also reported. 相似文献
20.
Joseph Hakl 《Thermochimica Acta》1984,80(2):209-219
The instrument described is suitable for the investigation of the thermal behaviour of substances and reaction mixtures under production conformable conditions; this is made possible by the sophisticated design of the sample chamber: easy stirring of the samples, measuring under any gas atmosphere and while bubbling gas through the sample, choice of the sample container and visual observation during the measurement. The control device allows the choice of one of three operational modes: constant temperature, linear increase in temperature, and adiabatic control; this permits the application of the SEDEX apparatus for a variety of methods including dynamic scanning, isoperibolic measurements, and (quasi) adiabatic studies. 相似文献