The N-hydroxyazetidines and are prepared startinfrom 2,3-dihydroazete 1-oxides ( and 0 by reduction with sodium borohydride and by reaction with a nucleophile, respectively. The N-thydroxyazetidines and can be oxidized with mercury (II) oxide to the corresponding nitrones ; oxidation of the N-hydroxyazetidine (unsubstituted at C-4) with equivalent of lead tetraacetate tyields the N-tacetoxy β-lactam . 相似文献
Cyclic as well as acyclic ketones, both saturated and α,β-unsaturated, can be converted into their homologous enamines by Horner-Wittig reaction with -methyl--anilinomethyl diphenylphosphine oxide (). 相似文献
Depending upon the experimental conditions, t-butyl (1,5,7,8)-1-ethoxycarbonyl-8-hydroxy-2-oxa-6-azabicyclo[3.2.0]octane-7-carboxylate (2a) reacts with methanesulphonyl chloride to give predominantly the -methanesulphonyl derivative (2b), the -methanesulphonyl derivative (3a), or the -(methanesulphonyl)methane-sulphonyl derivative (6a). 相似文献
-aryl derivatives of 4-pyridine are novel examples of donor-acceptor dyes. -substituents in the -aryl group influence the spectra, such that the more electron-withdrawing lead to more bathochromic shifts. However, a 2-nitro substituent in the -aryl ring has surprisingly little influence on the absorption maximum. PPP-MO-CI calculations, and correlation and conformational analyses are applied to the study. 相似文献
4-Dimethylamino--triphenylmethylpyridinium chloride () reacts with primary but not secondary alcohols to produce trityl ethers in good yield; in addition, amines may be selectively - tritylated witth in the presence of alcohols. 相似文献
A convenient direct transformation of -nitrobenzyl 6-(1′-hydroxyethyl)-1-azabicyclo-(3.2.0)heptane-3,7-dione-2-carboxylate to -formimidoyl thienamycin utilizing the silylated derivative of -formimidoyl cysteamine is described. 相似文献
3-Indazol-3-one has been generated by thermolysis of (-azidobenzoyl)iminopyridinium ylide and trapped as its Diels-Alder cycloadducts with several dienes. 相似文献
A quinolone quinone methide (; R=Me), prepared from 1,3-dimethyl-4- hydroxy-2-quinolone () and DDQ, reacted readily with -methylflindersine () to give a single cyclo-addition product (). 相似文献
The 4p photoelectron spectra of metallic Nb, Mo, Ru and Rh have been recorded. By use of a deconvolution procedure it is shown that the 4p spin-orbit component has a linewidth which significantly exceeds that of the 4p component. This suggests that N2N3N45 super Coster Kronig processes give a considerable contribution to the decay rata of the 4p hole state. 相似文献
In CFCl3, aziridines react with F2(6 %/N2, 20°C), COF2 (20 %/N2, 40°C) and CF3OF [1] (20 %/N2, 40°C).Substitution products are obtained : l-(aziridine)carbonyl fluorides and l-Fluoroaziridines In (Et)2O, aziridines react with COF2 (20 %/N2, 10°C) and we have the carbonyl fluorides . Products IV can be thermally decomposed into β fluoro isocyanates.In CFCl3, N substituted aziridines react with F2(6%/N2, 20°C) and with CF3OF [2] (20%/N2, 40°C). No reaction is observed with COF2in our conditions (5% to 25%/N2, 80°C to + 40°C).Addition products are obtained : N Fluoro amines β fluorinated , N Fluoro and NN difluoro amines β trifluoro methoxylated and .with R = SO2Ø, COØNO2, Cl. 相似文献
the title -acyl-derivatives react with -BuLi and Grignard reagents leading to products, which, formally, can be considered as derived from a Claisen-type condensation reaction. 相似文献
Reaction of benzilmonohydrazone(1) with S4N4 gives the azine (6) and not the 2--imidazole (2); this invalidates the claim that (2) is not the intermediate in the formation of -benzoyltriphenylimidazole from benzil and ammonia. S4N4 converts diphenylketene into thiobenzophenone. 相似文献
In strong base, e.g., sodium hydride in dimethylformamide, -(-azidobenzoyl)arylamines cyclise in high yield to 2-aryl-1,2-dihydro-3-indazolin-3-ones. 相似文献
Photoexcited 1, 4-dimethylcytosine (I) adds isopropanol to form 5,6-dihydro-1, 4-dimethyl-6-(2-hydroxy-2-propyl)cytosine (II) as the major product; a small amount of 5,6-dihydro-1-methyluracil (III) is formed as well. 相似文献
Dimethylphosphoramides react with -chloroperoxybenzoic acid (MCPBA) in anhydrous acetone to yield the previously unknown -dimdethylamino-oxyphosphonous derivatives -oxidation and rearrangement. Further MCPBA oxidation yields formaldehyde and nitrosomethane, isolated as its -dimer. These reactions provide a possible biomimetic model for the metabolic activation of hexamethylphosphoramide as a mutagen and carcinogen. 相似文献
Microwave—optical double resonance signals have been detected in a mass-selected ion-beam spectrometer for 12C16O+. With the optical excitation of fluorescence from the R1 () line of the (0,0) band of the A2Π ← X2∑ transition of 20350.6 cm?1, the microwave resonances occurred at 118101.8 ± 0.2 MHz and at 117694 ± 2 MHz corresponding to the N= 1, J = ← N = 0, J = and the N = 1, J = ← N = 0, J = transitions. 相似文献
The details and principles of an apparatus built for measurements of fluorescence quantum yields and cascade-free lifetimes of open-shell cations are reported. These rely on the detection of coincidences between energy selected photoelectrons and undispersed photons. The results of such measurements for CO+2, COS+, CS+2 and N2O+ in selected vibrational levels of their excited states are presented. Non-unity fluorescence quantum yields are found for some vibronic levels of CO+2(), COS+ (), N2OP+() and a non-exponential decay is observed for CS+2(). The data yield the following values for the radiative lifetimes: CO+2() 124 ± 6 ns, CO+2() 140 ± 7 ns, COS+() 550 ± 50 ns and N2O+() 240 ± 12 ns. 相似文献
Superoxo Co(III) complexes, [Co(CN)5O2][X]3 where X = Et3N+ and (Ph3P)2N+, mediate the dioxygen incorporation into 2,6-di--butylphenols () with the same regioselectivity as that in the base-catalyzed oxygenation of . The superoxo species acts as a base but is not incorporated into the substrate. 相似文献
Transformation of 6- and 5,6-dialkyl-2-methoxy-4(3H)-pyrimidinones (1a and 1b) into 1--acylated-pyrimidine derivatives 3(-) under Friedel-Craft like conditions is presented. In different acylation conditions 4-O-acylated-pyrimidines (5a and 5b) are also obtained. Compounds (3c) and (3f) can be directly converted into 1--acyl-protected-isouridine analogues (8a and 8b). 相似文献