ChemInform Abstract: Synthesis and Biological Activity of Aromatic Amino Acid Phosphoramidates of 5-Fluoro-2′-deoxyuridine and 1-β- Arabinofuranosylcytosine: Evidence of Phosphoramidase Activity (original) (raw)
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ChemInform Abstract: SYNTHESIS OF 2-(PYRIMIDIN-1-YL)- AND 2-(PURIN-9-YL)-2-AMINO ACIDS
Chemischer Informationsdienst, 1979
ChemInform Abstract Aus den Acetoxyaminosäurederivaten (I) entstehen in Gegenwart von Triethylamin bei der Behandlung mit Pyrimidyl-Derivaten (II) die Kondensationsprodukte (III), eine andere Reaktionsmöglichkeit von (I) besteht in der Umsetzung mit silylierten rimethylsiloxy-pyrimidinen wie (IV) unter Zusatz von Zinntetrachlorid, wobei z.B. (V) entsteht. Analoge Reaktionen erfolgen mit entsprechenden Purin-Derivaten wie (VI) zu (VII). Folgereaktionen liefern z.B. aus (VIIIa) das Mercaptoderivat (VIIIb). Als Zwischenstufe in der ondensation von (I) wird ein Acyliminderivat der Art (IX) angenommen; das zur Bildung einer solchen Zwischenstufe nicht befähigte Methyl-Analogon (X) reagiert mit (II) lediglich zur Dehydroverbindung (XI), während das erwartete Kondensationsprodukt (XII)über das Silyloxy-Derivat (IV) hergestellt werden muss, (IR-, UV-, NMR-, Massen-Spektren).
Chemische Berichte, 1981
Aus den Riburonamid-hydrazonen 4ac wurden in einer Eintopfreaktion regio-und stereoselektiv die 5'-Saureamid-Derivate des 3,5-Dimethylpyrazol-nucleosids 6a,c, der funktionell substituierten Pyrazol-nucleoside 9a und 10b und des 1 H-l,2,4-Triazol-nucleosids 18 direkt aufgebaut. Als Allopurinolribosid-Derivate wurden aus 9a und 10b die ungeschutzten Pyrazolo[3,4-d]pyrimidin-nucleosid-5'-saureamide 14a und 15 b hergestellt. Entsprechend wurde aus 18 das Ethylamid 20 der VirazoL5'-saure erhalten.
Zeitschrift für Naturforschung B, 1995
The reaction of 6-phenyl-3-pentafluorophenoxy-tetrafluorocyclohexa- 2,4-dien-1-one (1) with one equivalent of triphenylphosphane leads to the spectroscopically detectable 5-phenyl-4-pentafluorophenoxy- 3,3,6,6-tetrafluoro-2-triphenylphosphoranylidene- 4-cyclohexen-1-one (2), which upon hydrolysis or reaction with hydroxyl groups of the glass surface yields 5-phenyl-4-pentafluorophenoxy- 6,6-difluoro-2-triphenylphosphoranylidene- 4-cyclohexene-1,3-dione (3). The structure of 3 was determined by NMR measurements and an X-ray diffraction study.
ChemInform Abstract: FURAN DERIVATIVES. CXLI. OPENING OF THE FURAN RING IN 5-AZIDO-2-FURALDEHYDE
Chemischer Informationsdienst, 1980
ChemInform Abstract Die Titelverbindung (I) reagiert mit Phenylhydrazin (II) in Gegenwart von Base unerwartet zum Pyrazol (III), das auch schrittweise,über das acyclische Phenylhydrazon (IV), erhalten werden kann. Die weiteren Reaktionen von (I) mit dem Diamin (V) zum Chinoxalin (VI) bzw. mit dem Uracilderivat (VII) zum Uracilderivat (VIII) zeigen, dass (I) unter Igondensation an d/erv Aldehydgruppe und unter Ringspaltung reagiert.
Helvetica Chimica Acta, 1990
Glycolaldehyde phosphate aldomerizes in aqueous NaOH solution to a product mixture containing the racemates of the two diastereoisomeric tetrose 2,4-diphosphates and eight hexose 2,4,6-triphosphates. At room temperature in the absence of air and after 7 days, a solution 0 . 0 8~ in glycolaldehyde phosphate (= formylmethyl dihydrogenphosphate) and 2M in NaOH gives products, in up to 80% yield, with a tetrose/hexose derivative ratio of ca. 1 : 10 and with rue-allose 2,4,6-triphosphate comprising up to 50% of the mixture of sugar phosphates. When the reaction is run under the same conditions but in the presence of 0.5 mol-equiv. of formaldehyde, sugar phosphates are formed in up to 45% yield, with pentose 2,4-diphosphates now predominating over hexose triphosphates by a ratio of 3:1. rue-Ribose 2,4-diphosphate is found to be the major component, the ratios among ribose, arabinose, lyxose, and xylose 2,4-diphosphates being 52:14: 23: 11 in a representative experiment. The pentose diphosphates are constitutionally stable under the reaction conditions (observed for 23 weeks), but the diastereoisomeric ratios slowly change with time (to 22:34:30:14 after 23 weeks), showing that ribose 2,4-diphosphate is not the thermodynamically favored diastereoisomer. The observed product distributions in both the pentose and the hexose series (after 1 week) reveal an aldolization mode that is preferentially erythro in the product-determining step (the reaction of glycolaldehyde phosphate as its enolate with glycerinaldehyde 2-phosphate and tetrose 2,4-diphosphdte, respectively). An attempt is made to rationalize both this fact and the kinetic predominance of ribose 2,4-diphosphate in the pentose series and allose 2,4,6-triphosphate in the hexose series. Their configuration along the C-chain can be interpreted as corresponding to a minimum number of 1-5 repulsions in the packing of phosphate and OH substituents and minimal steric interaction between substituents at the reaction centers in the transition state of the product-determining step. The aldomerization of glycolaldehyde phosphate in the presence of formaldehyde is a variant of the formose reaction. It avoids the formation of complex formose product mixtures, largely as a consequence of the fact that aldoses which are phosphorylated at the C(2) 4. Mitteilung uber die Chemie von a -Aminonitrilen. 3. Mitteilung: [I].
Synthesis of furanoid sugar amino acids starting from fermentatively produced 2-Oxo-D-gluconic acid
Zeitschrift fur Naturforschung B
2-Oxo-D-gluconic acid obtained by fermentation of D-glucose was used as starting material for syntheses of amino acids. We trapped the carbohydrate in its furanoid configuration and synthesized an αand an ω-amino acid. After deprotection of the hydroxyl groups the latter did not isomerize to the substituted piperidine (aza-sugar) as expected, but remained in the furanose form. The starting structure 2 was proven by crystal structure analysis. The conformational identification of the other substances was done by NMR measurements following known rules for furanoses.
Helv Chim Acta, 1990
Glycolaldehyde phosphate aldomerizes in aqueous NaOH solution to a product mixture containing the racemates of the two diastereoisomeric tetrose 2,4-diphosphates and eight hexose 2,4,6-triphosphates. At room temperature in the absence of air and after 7 days, a solution 0 . 0 8~ in glycolaldehyde phosphate (= formylmethyl dihydrogenphosphate) and 2M in NaOH gives products, in up to 80% yield, with a tetrose/hexose derivative ratio of ca. 1 : 10 and with rue-allose 2,4,6-triphosphate comprising up to 50% of the mixture of sugar phosphates. When the reaction is run under the same conditions but in the presence of 0.5 mol-equiv. of formaldehyde, sugar phosphates are formed in up to 45% yield, with pentose 2,4-diphosphates now predominating over hexose triphosphates by a ratio of 3:1. rue-Ribose 2,4-diphosphate is found to be the major component, the ratios among ribose, arabinose, lyxose, and xylose 2,4-diphosphates being 52:14: 23: 11 in a representative experiment. The pentose diphosphates are constitutionally stable under the reaction conditions (observed for 23 weeks), but the diastereoisomeric ratios slowly change with time (to 22:34:30:14 after 23 weeks), showing that ribose 2,4-diphosphate is not the thermodynamically favored diastereoisomer. The observed product distributions in both the pentose and the hexose series (after 1 week) reveal an aldolization mode that is preferentially erythro in the product-determining step (the reaction of glycolaldehyde phosphate as its enolate with glycerinaldehyde 2-phosphate and tetrose 2,4-diphosphdte, respectively). An attempt is made to rationalize both this fact and the kinetic predominance of ribose 2,4-diphosphate in the pentose series and allose 2,4,6-triphosphate in the hexose series. Their configuration along the C-chain can be interpreted as corresponding to a minimum number of 1-5 repulsions in the packing of phosphate and OH substituents and minimal steric interaction between substituents at the reaction centers in the transition state of the product-determining step. The aldomerization of glycolaldehyde phosphate in the presence of formaldehyde is a variant of the formose reaction. It avoids the formation of complex formose product mixtures, largely as a consequence of the fact that aldoses which are phosphorylated at the C(2) 4. Mitteilung uber die Chemie von a -Aminonitrilen. 3. Mitteilung: [I].