- Structural, theoretical and multinuclear NMR study of mercury(II) complexes with a new ambidentate phosphorus ylide
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The reaction of the new ambidentate ylide, Ph3PCHCOCH 2COOC2H5 (EAPPY), with HgX2 (X = Cl, Br and I) in equimolar ratios using methanol as the solvent leads to binuclear complexes of the type [EAPPY·H
- Sabounchei, Seyyed Javad,Salehzadeh, Sadegh,Hosseinzadeh, Marjan,Bagherjeri, Fateme Akhlaghi,Khavasi, Hamid Reza
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experimental part
p. 2486 - 2492
(2011/10/18)
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- Monocyclic L-nucleosides, analogs and uses thereof
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Novel monocyclic L- nucleoside compounds have general formula (I). Embodiments of these compounds are contemplated to be useful in treating a wide variety of diseases including infections, infestations, neoplasms, and autoimmune diseases. Viewed in terms of mechanism, embodiments of the novel compounds show immunomodulatory activity, and are expected to be useful in modulating the cytokine pattern, including modulation of Th 1 and Th 2 response.
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- Silyl enol ethers as new protecting groups for alkyl 4-halo-3-oxobutanoates; the preparation of pure (3-alkoxycarbonyl-2-oxopropyl)triphenylphosphonium salts
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A new method has been developed for the preparation of pure (3-alkoxycarbonyl-2-oxopropyl)triphenyl-phosphonium salts 8. Alkyl 4-bromo-3-oxobutanoates and alkyl 4-chloro-3-oxobutanoates 7 are protected as the trimethylsilyl enol ethers prior to treatment of the resulting bromo(trimethylsilyl enol ether) esters 20c and 21c with triphenylphosphine in toluene and then addition of a little water to give pure (3-isopropoxycarbonyl-2-oxopropyl)triphenylphosphonium bromide 8c. Bromo(silyl enol ether) esters react more efficiently with triphenylphosphine than the chloro(silyl enol ether) esters. tert-Butyldimethylsilyl enol ethers of alkyl 4-bromo-3-oxobutanoates and alkyl 4-chloro-3-oxobutanoates 7 also react with triphenylphosphine. Protection of isopropyl 4-bromo-3-oxobutanoate 7c as the enol acetate followed by subsequent reaction with triphenylphosphine gives (Z)-(2-acetoxy-3-isopropoxycarbonylbut-2-enyl)triphenylphosphonium bromide 17.
- Moorhoff, Cornelis M.
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p. 1987 - 1995
(2007/10/03)
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- A New Preparative Route to 3-Unsubstituted Cephalosporins from Penicillin V
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p-Nitrobenzyl (2R,3R)-2-(benzothiazol-2'-yldithio)-α-isopropylidene-4-oxo-3-phenoxyacetylaminoazetidine-1-acetate (7), readily prepared from penicillin V, can be converted into the corresponding 2-allylthio compound (2) by addition of allyl bromide and sodium borohydride at a low temperature.This compound (2) on treatment with ozone, followed by cyclization with trimethyl phosphite, produces a 3H-ceph-3-em ester (4).The ester can be easily de-esterified to the free acid (1b).
- Davis, Michael,Wu, Wen-Yang
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p. 1591 - 1600
(2007/10/02)
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