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101.
E. M. Afsah M. M. Abou-Elzahab M. T. Zimaity G. R. Proctor 《Monatshefte für Chemie / Chemical Monthly》1984,115(8-9):1065-1070
When -keto-ester1 a was reacted with dimethyl acetylenedicarboxylate ring expansion occurred to give substituted cyclooctadienones.Michael reactions of the title compounds1 with unsaturated ketones gave adducts, some of which underwent further cyclization reactions. A new route to -tetralone ring system10 via cyclization of the intermediateMichael adduct9 is described.
Michael- und Ringerweiterungsreaktionen von 6-Carboethoxy-3,5-diaryl-2-cyclohexen-1-onen
Zusammenfassung Bei der Reaktion von -Keto-ester1 a mit Dimethyl-acetylendicarboxylat wurden unter Ringerweiterung substituierte Cyclooctadienone erhalten. DieMichael-Reaktion der Titelverbindung1 mit ungesättigten Ketonen ergab Addukte, von denen einige weitere Cyclisierungsreaktionen eingingen. Es wird ein neuer Weg zum -Tetralonsystem10 über die Cyclisierung des intermediärenMichael-Addukts9 beschrieben.相似文献
102.
Toshio Koizumi Jun Sakamoto Yasuhiko Gondo Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2002,40(14):2487-2494
The palladium(0)‐catalyzed polyaddition of bifunctional vinyloxiranes [1,4‐bis(2‐vinylepoxyethyl)benzene ( 1a ) and 1,4‐bis(1‐methyl‐2‐vinylepoxyethyl)benzene ( 1b )] with 1,3‐dicarbonyl compounds [methyl acetoacetate ( 4 ), dimethyl malonate ( 6 ), and Meldrum's acid ( 8 )] was investigated under various conditions. The polyaddition of 1 with 4 was carried out in tetrahydrofuran with phosphine ligands such as PPh3 and 1,2‐bis(diphenylphosphino)ethane (dppe). Polymers having hydroxy, ketone, and ester groups in the side groups ( 5 ) were obtained in good yields despite the kinds of ligands employed. The number‐average molecular weight value of 5b was higher than that of 5a . The polyaddition of 1b and 6 was affected by the kinds of ligands employed. The corresponding polymer 7b was not obtained when PPh3 and 1,2‐bis(diphenylphosphino)ferrocene were used. The polyaddition was carried out with dppe as the ligand and gave polymer 7b in a good yield. The molecular weight of the polymer obtained from 1b and 8 was much higher than those of polymers 5b and 7b . The polyaddition with Pd2(dba)3 · CHCl3/dppe as a catalyst (where dba is dibenzylideneacetone) produced polymer 9b in a 92% yield (number‐average molecular weight = 45,600). The stereochemistries of all the obtained polymers were confirmed as an E configuration by the coupling constant of the vinyl proton. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2487–2494, 2002 相似文献
103.
Bredikhina Z. A. Pashagin A. V. Savel"ev D. V. Bredikhin A. A. 《Russian Chemical Bulletin》2001,50(3):436-439
Nonracemic -blockers, viz., (S)-propranolol and (S)-timolol, were prepared from (S)-glycidol in three steps consisting in the reaction with SOCl2 followed by the reaction of the resulting (4S)-4-chloromethyl-2-oxo-1,3,2-dioxathiolanes with the corresponding phenol and the final cleavage of (4R)-aryloxymethyl sulfites under the action of amines in DMF. 相似文献
104.
V. A. Yanchenko A. M. Demchenko M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2004,40(4):516-518
We propose a method for obtaining derivatives of 7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine by alkylation of 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol by substituted -chloroacetanilides, followed by cyclization of the intermediate by phosphorus oxychloride. 相似文献
105.
Hiromu Hayashi 《Catalysis Surveys from Japan》1999,3(1):43-52
Additive telluromolybdates, MoO3·2TeO2 and MIIO·TeO2·MoO3 (MIITeMoO6; MII = Co, Mn, Zn), converted ethyl lactate selectively to pyruvate in a vaporphase fixedbed flow system at 250–300 °C. A synergy in activity was observed for binary TeO2–MoO3, and crystalline Te2MoO7 was suggested as the active species. The Rietveld analysis of powder XRD patterns of ternary CoTeMoO6 revealed the layer structure quite different from that of the reference Te2MoO7, but tellurium was again located adjacent to molybdenum linked through lattice oxygen. 相似文献
106.
The main product of the reaction of 1-methylcyclobutanol with Pb(OAc)4 in benzene is 1-phenyl-4-pentanone; the use of Mn(OAc)3 in acetic acid gives a mixture of 2,9-decanedione and methyl propyl ketone; 1-(chloro-, bromo-, thiocyano-, or cyano)-4-pentanone is formed in the presence of the systems Pb(OAc)4-metal halide or Mn(OAc)3-metal halide.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 12, pp. 2760–2763, December, 1992. 相似文献
107.
H. Viernstein S. Reiter P. Wolschann 《Monatshefte für Chemie / Chemical Monthly》1994,125(6-7):681-689
Summary The solubility enhancement of triflumizole, a systemic fungicide, by -cyclodextrin inclusion complexation was investigated by electron absorption spectroscopy. The respective association constant determined by different methods was estimated to 470±20M
–1 in aqueous solution. A model for the host-guest complexation was deduced by molecular calculations.
Löslichkeitsverbesserung von Triflumizole durchHost-Guest-Complexierung mit -Cyclodextrin
Zusammenfassung Die Löslichkeitsverbesserung des systemischen Fungizids Triflumizole durch Komplexierung mit -Cyclodextrin wurde mittels Elektronenabsorptionsspektroskopie untersucht. Die entsprechende Stabilitätskonstante wurde durch verschiedene Methoden erfaßt und betrug im wäßrigen Medium 470±20M –1. Ein Model für denHost-Guest-Complex wurde durch Molekülrechnungen erstellt.相似文献
108.
A systematic extension of Ruedenberg's expansion formula is applied to evaluate two-electron integrals occurring in calculations on molecular structure. Minimum STO basis sets are used for all SCF-calculations within the framework of the MEDO-method (Multipole Expansion of Diatomic Overlap). The errors due to this approximation scheme are almost negligible compared to those introduced by the truncated basis set: LiH, Li2 and N2 are chosen as examples. 相似文献
109.
110.
Colin Thomson 《Theoretical chemistry accounts》1973,32(2):93-100
Non-empirical LCAO-MO-SCF calculations on SiF2 using two Gaussian basis sets are reported. The larger basis set gives a calculated geometry in good agreement with experiment. The effect on the energy and population analysis of optimization of the Si 3d exponent was investigated. 3d orbitals are found to be much less important in the bonding than in the isoelectronic molecule SO2. 相似文献