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Showing 1 to 20 of 24 for “"Methylene group"”.
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The Preparation of: 1. 1-(p-Methoxyphenyl)-2,6-dicarbethoxy-5-amino-cyclohexenone-3. 2. 1-(p-Methoxyphenyl)-2,6-dicarbethoxy-4-cinnamoyl-cyclohexane-dione-3,5. 3. diidodo derivative of 1-(p-Hydroxyphenyl)-2,6-dicarbethoxy-cyclohexane-dione-3,5.
For this type of reaction to tabs place, the methylene group requires the activating influence of an adjacent CC, -CN, or -NO2 grouping. A heterocyclic, or an aromatic group, or a conjugated system have the same effect.
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The synthesis and reactions of deoxyvasicinone and analogous compounds
… of a pseudo-enamine. Deprotonation at the C-3 methylene group of 2,3-dihydro-pyrrolo[2,1-b] quinazolin-9( 1H)-one and 2,3-dihydro-1,1-dimethylpyrrolo [2,1-b]quinazol in-9(1H)-one was achieved using lithium diisopropylamide and the lithiated species were used in situ for further synthetic …
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Mössbauer studies of putidaredoxin
… of an enzyme system which hydroxylates a methylene group with O2 to form a secondary alcohol. It contains, in a molecular weight of 12,000, two atoms each of iron and acid labile sulfur. We have used the Mossbauer effect to study the symmetry of the ligands and the electronic configuration …
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The synthesis and reactions of sulphur analogues of deoxyvasicinone
… (A) and (B) were shown to react (at the methylene group alpha to the carbon-nitrogen double bond) with a variety of electrophiles at elevated temperatures. Compound (C) was found to be inert to electrophiles under the same reaction conditions.<br/><br/>The ability of the heterocycles …
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Novel small molecules for modulation of bacterial signaling pathways
… where the reaction was favored at the C5 bromo methylene group over the C4 bromine substituent of fimbrolides. Applying the Suzuki coupling reaction, various mono and di-aryl substituted fimbrolide analogues were synthesized where the aryl substitution also favored at the C5 bromo methylene …
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ΣΧΕΔΙΑΣΜΟΣ ΚΑΙ ΣΥΝΘΕΣΗ ΝΕΩΝ ΠΥΡΕΘΡΟΕΙΔΩΝ
… CONSISTS OF A MIDDLE PART MADE UP OF AN ESTER GROUP OR ANOTHER ISOSTERIC GROUP, WHICH IS CONNECTED TO A SUBSTITUTED OR UNSUBSTITUTED METHYLENE GROUP AND A GEM-DIMETHYL GROUP OR ANOTHER EQUIVALENT GROUP PLACED IN B POSITITON TO THE ESTER GROUP, AND OF TWO UNSATURATED CENTRES BOUND ON EITHER SIDE …
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Studies of paclitaxel analogs modified in ring C
… of paclitaxel. The inactivity of the C-6 methylene group towards chemical modifications has been overcome by the formation of a double bond at the C- 6 and C-7 positions. Modification of the C-6 position has been achieved for the first time and over 20 new paclitaxel analogs modified at …
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The synthesis and reactions of thienopyridines
… CO<sub>2</sub>Me, CO<sub>2</sub>Et) containing methylene groups activated by the nitrile or ester functionality is described. Derivatives (A-D) are reacted with carbon disulfide in the presence of base, followed by alkylation with iodomethane, to afford novel thienopyridines (E-H; R = CN, …
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Reaction of CS2 and CO2 with Amidines and Guanidines
… reactivity depends on whether there is a methylene alpha to the amidine carbon. Having such a methylene group promotes the formation of trithioanhydride. A tetrahydropyrimidine having neither an N-H bond nor an alpha methylene forms an unstable zwitterionic adduct (B-CS2). The acyclic …
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Oxocarbenium Ion and Alkene Metathesis Strategies for the Synthesis of Complex Cyclohexanes
… oxygen of the parent sugar is replaced with a methylene group, have attracted interest as hydrolytically stable mimetics of their parent O-glycosides. This research reports the development of two general methodologies for the synthesis of highly oxygenated cyclohexanes: (1) Oxocarbenium Ion …
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A Study of some Complexes of Thallium and Tellurium
… study 1H n.m.r. spectra but no coupling of the methylene group with 125 Te was seen. Attempts were made to prepare telluroylids. Some use of diaryltelluride were investigated with the possible catalytic use of the diaryl telluride. The possible use of organotellurium compounds as dehalogenating …
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Synthesis and characterisation of biobased polyamides and their cellulose nanocomposites
… diffusion and the low ratio of amide to methylene group within the elastomer are proposed to be responsible for these extraordinary properties. The polymerisation time affect the properties of the elastomer. The use of the optimal PA36,36 in anti-corrosion coating, piezoresistive sensing …
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Understanding Heterogenous Catalysis on Zeolites and Manganese Oxides
… the elongation of the chain by just one methylene group from the optimum size has a major negative impact on the free energy within the zeolite. Finally, the effect of van der Waals (vdW) forces was quantified for the optimally sized alkyne. It was found that without the inclusion of vdW …
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Inhibitor studies on para-aminobenzoic acid synthase.
… of ADC was accomplished. An aromatic nitro group was reduced to give an amine using tin(II) chloride and hydrogenation reactions. Other forms of nitrogen protection using carbamates and bissilyl protection were also utilised. The formation of an enol pyruvyl group was accomplished in an …
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Reactions and properties of the isomeric dihydrothiophene 1, 1- dioxides
… 1,1-dioxide (I) is the parent member of a large group of five-membered cyclic β-sulfones while the 2,3-dihydrothiophene 1,1-dioxide (II) is the parent member of the corresponding α-sulfones. Structurally, I contains a carbon-carbon double bond, a sulfone group and two α-methylene groups while II …
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Advanced Polymeric Membranes and Multi-Layered Films for Gas Separation and Capacitors
… bisphenols. Two contained trifluoromethyl groups while the other two had methyl groups. The symmetric polymers had Tg's of approximately 160 °C while the asymmetric polymers showed higher Tg's near 180 °C. The symmetric polymers had breakdown strengths near 380 kV/mm at 150 °C. The …
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