- Cyclic ketones in spiroannulation
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Conversion of a cyclic carbonyl carbon into a quaternary carbon has been effected by a Wittig-Horner reaction with diethyl (N-benzyliden) aminomethylphosphonate and a subsequent alkylation with a protected vinyl ketone. The product was a substrate for spiroannulation after initial hydrolysis. The reaction sequence was carried out as a one-pot reaction. Copyright Taylor & Francis Group, LLC.
- Bjrnstad, Vidar,Undheim, Kjell
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Read Online
- Phosphorous acid analogs of novel P2-P4 macrocycles as inhibitors of HCV-NS3 protease
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HCV-NS3 protease is essential for viral replication and NS3 protease inhibitors have shown proof of concept in clinical trials. Novel P2-P4 macrocycle inhibitors of NS3/4A comprising a P1 C-terminal carboxylic acid have recently been disclosed. A series o
- Pompei, Marco,Francesco, Maria Emilia Di,Koch, Uwe,Liverton, Nigel J.,Summa, Vincenzo
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- Synthesis of diethyl α-(o-nitroaryl)phosphoglycines via oxidative nucleophilic substitution of hydrogen in nitroarenes
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The carbanion of protected diethyl phosphoglycinate adds to nitroarenes in liquid ammonia in ortho position to the nitro group. Subsequent oxidation of the resulting adduct σH with potassium permanganate gave N-protected diethyl α-(o-nitroaryl)phosphoglycinates. Georg Thieme Verlag Stuttgart New York.
- Makosza, Mieczysaw,Sulikowski, Daniel
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scheme or table
p. 1666 - 1668
(2010/08/22)
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- 1-Azidoalkylphosphonates - A convenient substrates for the synthesis of N-alkyl α-aminoalkylphosphonates
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Diethyl [1-(alkylamino)alkyl]phosphonates 5 have been efficiently synthesized via a two-step reaction of diethyl 1-azidoalkylphosphonates 1 with triphenylphosphine, followed by in situ transformation of thus formed phosphazenes 2 into imines 4 by means of
- Gajda,Janik
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p. 493 - 498
(2007/10/03)
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- 1,3-Dipolar cycloaddition of several azomethine ylides to [60]fullerene: Synthesis of derivatives of 2′,5′-dihydro-1′H-pyrrolo[3′,4′:1,2][60]fullerene
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Imines 1 have been prepared by the condensation of benzaldehyde and corresponding primary amines in which the ester group, phosphonate ester group and depsipeptide are introduced. [60]Fullerene reacts with imines 1 to give the corresponding isomers of fullerene-fused proline derivatives 2 via a process of 1,3-dipolar cycloaddition. 1,3,5-Tris(ethoxycarbonylmethyl)perhydro-1,3,5-triazine 4, which has been prepared by the condensation of ethyl glycinate with paraformaldehyde, depolymerizes thermally to provide an azomethine ylide which reacts with [60]fullerene to afford ethyl 2′,5′-dihydro-1′H-pyrrolo-[3′,4′:1,2][60] fullerene-2′-carboxylate 5. 2-Phenyl-4,5-dihydrooxazol-5-one 6 tautomerizes thermally to form the mesoionic oxazolium 5-oxide 6a, which then, as a cyclic azomethine ylide, combines further with [60]fullerene to give 5′-phenyl-2′H-pyrrolo[3′,4′:1,2][60]fullerene 7 which possesses Cs symmetry.
- Wu, Shi-Hui,Sun, Wei-Quan,Zhang, Dan-Wei,Shu, Lian-He,Wu, Hou-Ming,Xu, Jing-Fei,Lao, Xia-Fei
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p. 1733 - 1738
(2007/10/03)
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- On the stereochemical purity of (+)-7-aminocephalosporanic acid
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(±)-7-Aminocephalosporanic acid (18a) and (±)-7-epi- aminocephalosporanic acid (4a) have been synthesized. A chiral HPLC method has been developed for the separation of the four stereo-isomers. Natural (+)-7-aminocephalosporanic acid (1) was demonstrated to he enantiomerically (ee >> 99.95%) and diastereomerically (de >>99.95%) pure.
- Oberhauser, Thomas,Meduna, Vladimir
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p. 7691 - 7702
(2007/10/03)
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- α-Aminophosphonates. III. Cycloaddition anionique-1,3 des esters α,β-insatures: Preparation et transformations des Δ1-pyrrolines
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The anions of the 2-azaallylphosphonates 1 react with the α,β-unsaturated esters 2 to yield intermediates 4'.These intermediates form the 2-diethoxyphosphonyl-4-ethoxycarbonylpyrrolidines 4 following a protonation while an elimination of the anion of the
- Dehnel, Andre,Kanabus-Kaminska, Jolanta M.,Lavielle, Gilbert
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p. 310 - 318
(2007/10/02)
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- PO-Activated Olefination and Conversion of Aldehydes and Ketones to Higher Amines; II. Synthesis of Arylethylamines
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The transformation of arylcarboxaldehydes and/or - ketones 2 by three different routes into arylethylamines 3 and/or 4 is reported.According to the first route, the intermediate iminophosphonates 9 react through a classical PO-activated olefination.The second and the third involve the rearrangement of the iminophosphonates 9 into the vinylphosphoramidates 12.
- Heymes, A.,Chekroun, I.
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p. 245 - 249
(2007/10/02)
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- A CONVENIENT SYNTHETIC METHOD FOR SCHIFF BASES. THE TRIMETHYLSILYL TRIFLUOROMETHANESULFONATE-CATALYZED REACTION OF N,N-BIS(TRIMETHYLSILYL)AMINES WITH ALDEHYDES AND KETONES
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N,N-Bis(trimethylsilyl)amines react with aldehydes or ketones in the presence of trimethylsilyl trifluoromethanesulfonate to give Schiff bases in high yields.In situ utilization of the reaction solution as the Schiff base is also demonstrated.
- Morimoto, Toshiaki,Sekiya, Minoru
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p. 1371 - 1372
(2007/10/02)
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- Process for the preparation of β-cyclo-substituted ethylamines
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The present invention provides a multistep process for the preparation of β-cyclo-substituted ethylamines of the general formula:- in which AR is a heterocyclic or non-heterocyclic aromatic radical, which is optionally mono- or poly- substituted, wherein said compounds represent a class of intermediates which can be converted to 4,5,6,7-tetrahydro[3,2-C] or [2,3-C]pyridines wherein the latter are useful for anti-inflammatory, vasodilator or blood platelet aggregation inhibition activities.
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- Cephalosporin compounds
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Novel 7-azido-3-cephem compounds are prepared via α-amino-phosphonoacetate esters. The cephem compounds are intermediates for the preparation of novel and known useful antibiotic cephalosporins.
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