- A novel and simple route for the synthesis of 3,4-disubstituted pyrroles
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A new class of 3,4-disubstituted pyrroles has been prepared by the reaction of 1-aroyl-2-arylsulfonylethenes and 1,2-diarylsulfonylethenes with tosyl methyl isocyanide.
- Padmavathi, Venkatapuram,Reddy, Boggu Jagan Mohan,Padmaja, Adivireddy
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p. 333 - 335
(2007/10/03)
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- A novel route for the synthesis of unsaturated oxo sulfones and bissulfones
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The reaction between vinyl chloride and aroyl/arylsulfonyl chloride under Friedel-Craft's reaction conditions was the basis for the synthesis of unsaturated oxo sulfones and bissulfones.
- Reddy, D. Bhaskar,Babu, N. Chandrasekhar,Padmavathi,Sumathi
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p. 491 - 494
(2007/10/03)
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- Efficient preparation of E-β-iodovinyl phenylsulfone by finkelstein reaction at a vinylic center
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Treatment of E-β-chlorovinyl phenylsulfone, a crystalline compound that can be conveniently prepared on a large scale from 1,1,2-trichloroethane, by sodium iodide in acetone at ca 130 °C, in a sealed vessel, affords the title iodosulfone in good yield.
- Zoller,Uguen,De Cian,Fischer
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p. 8089 - 8092
(2007/10/03)
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- Approaches to 2,6-Diaryl-3,7-DioxabicycloOctane Lignans via Asymmetric Synthesis of Dihydro- and Tetrahydro-furan Derivatives
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Cyclisation of chiral non-racemic phenylsulphonylvinyl epoxy ethers, produced using the Sharpless epoxidation reaction, has been used to prepare a series of enantiomerically enriched 2-aryl-4-(α-hydroxybenzyl)-4,5-dihydrofuran derivatives.Reduction of these compounds using triethylsilane and BF3-diethyl ether gave the corresponding tetrahydrofuran derivatives stereoselectively.Attempts to convert either the dihydro- or tetrahydro-furan derivatives into lignans belonging to the 2,6-diaryl-3,7-dioxabicyclooctane series so far proved unsuccessful.
- Pelter, Andrew,Ward, Robert S.,Little, Gillian M.
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p. 2775 - 2790
(2007/10/02)
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- Reactions of Alkylmercurials with Heteroatom-Centered Acceptor Radicals
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The relative reactivities of alkylmercury halides toward PhS., PhSe., or I. decrease drastically from R = tert-butyl to R = sec-alkyl to R = n-butyl, indicative that R. is formed in the rate-determining step in the attack of these radicals upon RHgCl.The alkyl radicals thus formed will enter into chain reactions in which a heteroatom-centered radical (A.) is regenerated from substrates such as RS-SR, ArSe-SeAr, ArTe-TeAr, PhSe-SO2Ar, Cl-SO2Ph; ZCH=CHA (A = Cl, I, SPh, SO2Ph); or PhCCHA (A = I, SPh, SO2Ph). β-Styrenyl (PhCH=CHA, Ph2C=CHA) and β-phenethynyl (PhCCA) systems with A = I, Br, SO2Ph also enter into chain reactions with mercury(II) salts with the ligands PhS, PhSe, PhSO2, or (EtO)2PO.The relative reactivities of a series of reagents toward t-Bu. and of PhCH=CHA, Ph2C=CHA, and PhCCA toward c-C6H11. are reported as well as the regioselectivity of t-Bu. attack observed for 1,2-disubstituted ethylenes (ZCH=CHA) with Z and A from the group Ph, Cl, Br, I, SO2Ph, SPh, Bu3Sn.Reactions of (E)- and (Z)-PhCH=CHI or MeO2CCH=CHI with t-Bu. or c-C6H11. occurred in a regioselective and stereospecific (retention) manner.Reactions of (E)- and (Z)-ClCH=CHCl occurred in a nonstereospecific manner in which the E/Z product ratio increased with the bulk of the attacking radical.A similar effect on the E/Z product ratios was observed for (Z)-MeO2CCH=CHCl.
- Russell, Glen A.,Ngoviwatchai, Preecha,Tashtoush, Hasan I.,Pla-Dalmau, Anna,Khanna, Rajive K.
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p. 3530 - 3538
(2007/10/02)
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- CYCLOFUNCTIONALISATION OF EPOXYALCOHOL DERIVATIVES. 1. DELIVERY OF FUNCTIONALISED CARBON FOR STEREOSPECIFIC SYNTHESIS OF DIHYDROFURANS AND DIHYDROXYACIDS
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E-2-(Phenylsulfonyl)vinyl ethers of 2,3-epoxyalcohols are stereospecifically rearranged to 3-(phenylsulfonyl)-4-(1-hydroxyalkyl)-4,5-dihydrofurans on treatment with LDA.Oxidation of these compounds or the derived des-sulfonyl compounds provides esters or lactones which correspond to regiospecific delivery of -CO2H or -CH2CO2H to C-2, with inversion.
- McCombie, Stuart W.,Shankar, Bandarpalle B.,Ganguly, Ashit K.
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p. 6301 - 6304
(2007/10/02)
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- A NEW SYNTHESIS OF γ-HYDROXYVINYLSTANNANES AND SILANES UTILIZING β-STANNYLVINYL AND β-SILYLVINYL SULFONES
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β-Stannylvinyl sulfone 1 (new compound) and β-silylvinyl sulfone 2 on sequential treatment with Bu3SnLi and aldehydes afforded γ-hydroxyvinylstannanes 6 and silanes 7, respectively, in good yields.From β-chlorovinyl sulfones 9 and 10 stannanes 11 were prepared.The stannanes 11 were shown to be useful for the synthesis of α,β-unsaturated γ-lactones 12.
- Ochiai, Masahito,Ukita, Tatsuzo,Fujita, Eiichi
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p. 4025 - 4028
(2007/10/02)
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