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  • 1
    Electronic Resource
    Electronic Resource
    The Phosphonate-Phosphate- and Phosphate-Phosphonate Rearrangement and Their Applications, 4Part 3: Ref.[1].. Deprotonation of Secondary Benzylic Phosphates  -  Configurationally Stabile Benzylic Carbanions with a Diethoxyphosphoryloxy Substituent and Their Rearrangement to Optically Active Tertiary α-Hydroxyphosphonates (1996)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 1503-1508 
    Details
    ISSN: 0009-2940
    Keywords: Phosphate - Phosphonate rearrangement ; Carbanions, benzylic, configurational stability of ; α-Hydroxyphosphonates, tertiary, chiral, non-racemic ; t-Butyl(phenyl)phosphinothioic acid, homochiral ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Optically active alcohols (ee ≥ 98%) such as 1-phenylpropanol, 1-(2-naphthyl)ethanol, 1-tetralol, and 1-indanol were transformed into diethyl phosphates 7a-d. sBuLi/TMEDA  -  induced phosphate - phosphonate rearrangement in diethyl ether furnished tertiary α-hydroxyphosphonates 8a-d of high enantiomeric purity (ee 94-98%) in yields of 43-83% with retention of configuration. The enantiomeric excesses were determined by using homochiral t-butyl(phenyl)phosphinothioic acid as chiral solvating agent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19961291217
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  • 2
    Electronic Resource
    Electronic Resource
    Chiral Carbanions, 1. Configurational Stability and Reactions of α-Acyloxy-Substituted α-Methylbenzyllithium Compounds (1995)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 128 (1995), S. 1069-1077 
    Details
    ISSN: 0009-2940
    Keywords: Esters, 1-phenylethyl ; Carbanions, α-methyl-α-oxybenzyl, Configurational stability ; Ester - hydroxy ketone rearrangement ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Racemic and optically active 1-phenylethyl esters of pivalic, ( - )-camphanic and 2,4,6-triisopropylbenzoic acid were prepared. The esters 7a of pivalic acid were deprotonated with lithium 2,2,6,6-tetramethylpiperidide (Li-TMP) to form α-oxy-α-methylbenzyllithium compounds which are partly con-figurationally stable prior to acylation with starting material. Camphanic ester (-)-7b cannot be deprotonated by Li-TMP and tBuLi is added to the ester function to afford ketone (-)-12a. 1-Phenylethyl 2,4,6-triisopropylbenzoates 16 were transformed within minutes to carbanions 19 by using sBuLi/TMEDA in THF, hexane, toluene and sBuLi without TMEDA in toluene/20% diethyl ether at -78°C. The carbanions are configurationally stable only in toluene/20% diethyl ether and racemise partly in the other solvents. They react with a variety of electrophiles with either retention [MeOD, AcOD, (MeO)2CO, CICO2Me] or inversion (Me3SnCl) of configuration. Carbanions 19 rearrange on warming to -20°C to hydroxy ketone 24 with racemisation.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19951281103
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  • 3
    Electronic Resource
    Electronic Resource
    Configurational Stability and Stannylation of Dipole-Stabilised Cyclic Tertiary Benzylic α-Oxycarbanions, which Occurs with Retention or Inversion of Configuration Depending on R and X of R3SnX Used (1999)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 3511-3518 
    Details
    ISSN: 1434-193X
    Keywords: 2,4,6-Triisopropylbenzoates, 1-indanyl, 1,2,3,4-tetrahydro-1-naphthyl ; N,N-Diisopropylcarbamate, 1-indanyl ; Carbanions, configurational sStability ; Stereochemistry, stannylation ; Liquid chromatography, determination of ee ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2,4,6-Triisopropylbenzoates of 1-indanol and 1-tetralol (ee 98%) are deprotonated at -78 °C in hexane by sBuLi/TMEDA to give partly configurationally labile organolithium intermediates 5a and 5b, which are deuterated by MeOD with retention of configuration. These intermediates are stannylated by trimethyltin chloride with inversion as determined by lithiodestannylation followed by addition of MeOD to produce deuterated esters of low ee. Stannylation of (S)-5b with (-)-menthyldimethyltin bromide affords stannane 7 (de ≥ 95%) with inversion. The carbanion derived from (S)-1-indanyl N,N-diisopropylcarbamate (9) is configurationally stable. It reacts with trimethyltin chloride favouring inversion of configuration (ee up to 17%). Tributyltin chloride and tributyltin triflate yield stannanes 11b of opposite stereochemistry, the latter giving retention of configuration. Tributyltin bromide behaves similarly to the chloride, but the ee of the reaction product is only about 30%.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Neuartige synthetische Aspekte der Phosphonat-Phosphat-Umlagerung, 1. Ein allgemeiner Zugang zu 1,2-Propadienylphosphaten (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 3891-3897 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel Synthetic Aspects of the Phosphonate-Phosphate Rearrangement, 1. An Useful Approach to 1,2-Propadienyl PhosphatesAcylphosphonates 1 react with 1-alkynes 2 in toluene to give dialkyl (1-hydroxy-2-alkynyl)phosphonates 3. These rearrange in alcohol/sodium alkoxide to 2-propynyl phosphates 4 and 1,2-propadienyl phosphates 5. Using dimethyl sulfoxide/sodium bis(trimethylsilyl)amide the compounds 5 are produced as main products.
    Notes: Aus den Acylphosphonaten 1 und den 1-Alkinen 2 werden in Toluol die Dialkyl-(1-hydroxy-2-alkinyl)phosphonate 3 synthetisiert. Diese lagern sich in Alkohol/Na-Alkoxid zu den 2-Propinyl-phosphaten 4 und den 1,2-Propadienyl-phosphaten 5 um. In Dimethylsulfoxid/Natrium-bis(trimethylsilyl)amid erhält man hauptsächlich 5.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801131220
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  • 5
    Electronic Resource
    Electronic Resource
    Ein einfacher Weg zu D-Apio-β-D-furanosyl- und 2′-Desoxyapio-β-D-furanosylnucleosiden (1995)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 551-558 
    Details
    ISSN: 0947-3440
    Keywords: Apionucleosides ; Nucleosides ; Antiviral agents ; Tris(trimethylsilyl)silane ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A Convenient Route to D-Apio-β-D-furanosyl- and 2′-Deoxyapio-β-D-furanosyl Nucleosides2,3-O-Isopropylidene-D-apio-β-D-furanose (1), available in 40% overall yield by modified literature procedures, is acylated regioselectively to the new 3′-O-benzoyl-derivative 2. This is converted to the anomeric triacetates 4 (β-4; α-4 = 1.8:1) by cleavage of the isopropylidene protecting group from 2 followed by peracetylation. Reaction of compounds 4 with silylated nucleobases and subsequent deprotection gives the D-apio-β-D-furanosyl nucleosides 8-10 in good yields. Regioselective hydrazinolysis of the protected nucleosides 5 and 6 affords the 2′-hydroxy-derivatives 11 and 12, respectively, which are converted to the 2′-deoxyapio-β-D-furanosyl nucleosides 17 and 18, respectively, via deoxygenation of the corresponding thionocarbonates 13 and 14 with tris(trimethylsilyl)silane and subsequent deprotection. The 2′-deoxyapio-β-D-furanosyl cytosine 20 is prepared from the 2′-deoxyapio-β-D-furanosyl uracil derivative 16.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199519950375
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  • 6
    Electronic Resource
    Electronic Resource
    Ein einfacher Weg zu 3′-Desoxy-α-L- und 3′-Desoxy-β-D-apionucleosiden (1995)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 559-565 
    Details
    ISSN: 0947-3440
    Keywords: Apionucleosides ; Nucleosides ; Antiviral agents ; Branched nucleosides ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A Convenient Route to 3′-Deoxy-α-L- and 3′-Deoxy-β-D-apionucleosidesThe cyclic thionocarbonate 3, easily available in three steps from 3′-O-benzoyl-2,3-O-isopropylidene-D-apio-β-D-furanose (1), is deoxygenated with n-Bu3SnH to yield the 3′-deoxy epimers 4 [methyl 3-C-(benzoyloxymethyl)-3-deoxy-α-L-threo-tetrofuranoside] and 6 [methyl 3-C-(benzoyloxymethyl)-3-deoxy-β-D-erythro-tetrofuranoside]. These are separated by chromatography and further converted to the 3′-deoxy-α-L-apionucleosides 11-13, and the 3′-deoxy-β-D-apionucleosides 17-19, respectively.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199519950376
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  • 7
    Electronic Resource
    Electronic Resource
    Reaktionen mit phosphororganischen Verbindungen, XLIV Darstellung von 3-Oxo-1-alkenylphosphonsäure-dialkylestern (1979)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1979 (1979), S. 492-502 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Organophosphorus Compounds, XLIV. - Synthesis of Dialkyl 3-Oxo-1-alkenylphosphonatesThe Michaelis-Arbusov reaction of 2-chlorovinyl ketones 1 with trialkyl phosphites 2 gives 2-acylvinylphosphonates 3 as well as enolphosphates 4 and 3-oxo-1,1-alkanediyldiphosphonates 5. Using the Michaelis-Becker procedure only the compounds 4 and 5 are formed as demonstrated in the case of 4d and 5d. Reaction of trimethyl and triethyl phosphite (2a and 2b) with 2-chlorovinyl ketones 1a - 1d yields mixtures of products 3a-3e, 4a-4e and 5a-5e; whereas reaction with triisopropyl phosphite (2c) gives predominantly compound 3. For example, 2c and 1a react to form a mixture consisting mainly of 2-acylvinylphosphonate 3f and a small amount of 3-oxo-1,1-alkanediyldiphosphonate 5f. Only the 2-acylvinylphosphonate 3g is isolated on reaction of 2c with 1d.
    Notes: Die Umsetzung von 2-Chlorvinylketonen 1 mit Trialkylphosphiten 2 nach Michaelis-Arbusow führt nicht nur zu den erwarteten 2-Acylvinylphosphonaten 3, sondern auch zu den Enolphosphaten 4 und zu den 3-Oxo-1,1-alkandiyldiphosphonaten 5. Bei Anwendung der Michaelis-Becker-Variante entstehen jedoch ausschließlich die Verbindungstypen 4 und 5, wie anhand der Reaktionsprodukte 4d und 5d gezeigt werden konnte. Während Trimethyl- und Triethylphosphit (2a bzw. 2b) mit den 2-Chlorvinylketonen 1 a - 1d jeweils die Produktgemische 3a-3e, 4a-4e und 5a-5e liefern, entstehen bei Verwendung von Triisopropylphosphit (2c) bisweilen nur Reaktionsprodukte des im Titel genannten Typs 3. So liefert 2c mit 1a nur ein Gemisch aus der Hauptmenge des 2-Acylvinylphosphonats 3f und des in untergeordneter Menge auftretenden 3-Oxo-1,1-alkandiyidiphosphonats 5f. Nach Umsetzung von 2c mit 1d wird als definiertes Reaktionsprodukt nur noch das 2-Acylvinylphosphonat 3g isoliert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197919790410
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  • 8
    Electronic Resource
    Electronic Resource
    Biosynthese von Naturstoffen mit einer P—C-Bindung, I. Einbau von D-[6,6-D2]Glucose in (2-Aminoethyl)phosphonsäure in Tetrahymena thermophila (1988)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1988 (1988), S. 531-535 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Biosynthesis of Natural Products with a P—C Bond, I. - Incorporation of D-[6,6-D2]Glucose into (2-Aminoethyl)phosphonic Acid in Tetrahymena thermophilaThe phosphate-phosphonate rearrangement is tested as a model reaction for the biosynthesis of the P—C bond as alternative to the rearrangement of phosphoenolpyruvate. D-[6,6-D2]glucose was prepared and added to the growth medium of Tetrahymena thermophila. (2-Aminoethyl)phosphonic acid (AEP) (1) was isolated from the wet cell mass by hydrolysis with 6 N HCl and ion exchange chromatography and was derivatized to the crystalline 4-bromobenzamide 26. The amount of [1,1-D2]-AEP in admixture with unlabeled AEP was up to 43%, which is not in agreement with an enzymic phosphate-phosphonate rearrangement of dihydroxyacetone phosphate, for which monodeutereated AEP would be expected. For comparison [1,1-D2]-AEP (31) was prepared starting from 2-amino-[1,1-D2]ethanol.
    Notes: Es wird untersucht, ob die Phosphat-Phosphonat-Umlagerung als Modellreaktion für die Biosynthese der P—C-Bindung als Alternative zur Umlagerung der Phosphoenolbrenztraubensäure dienen kann. D-[6,6-D2]Glucose wurde hergestellt und dem Nährmedium von Tetrahymena thermophila zugefügt. Aus der feuchten Zellmasse wurde durch Hydrolyse mit 6 N HCl und Ionenaustauscherchromatographie (2-Aminoethyl)phosphonsäure (AEP) (1) gewonnen und in das kristalline 4-Brombenzamid 26 übergeführt. Der Gehalt an [1,1-D2]-AEP beträgt bis zu 43% neben im wesentlichen nichtmarkierter AEP, was mit einer enzymatischen Phosphat-Phosphonat-Umlagerung von Dihydroxyacacetonphosphat nicht vereinbar ist, für die monodeuterierte AEP zu erwarten wäre. Für Vergleichszwecke wurde ausgehend vom 2-Amino-[1,1-D2]ethanol durch Umfunktionalisierung [1,1-D2]-AEP (31) gewonnen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198819880607
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  • 9
    Electronic Resource
    Electronic Resource
    Biosynthese von Naturstoffen mit einer P—C-Bindung, II. Hydroxylierung von deuterierten (2-Aminoethyl)phosphonsäuren zu (2-Amino-1-hydroxyethyl)phosphonsäure in Acanthamoeba castellanii (Neff) (1988)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1988 (1988), S. 537-542 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Biosynthesis of Natural Products with a P—C Bond, II1). - Hydroxylation of Deuterated (2-Aminoethyl)phosphonic Acids to (2-Amino-1-hydroxyethyl)phosphonic Acid in Acanthamoeba castellanii (Neff)(2-Amino-1-hydroxyethyl)phosphonic acid (1) (OH-AEP) was transformed into the crystalline benzamide 11. (2-Amino-[1,1-D2]ethyl)phosphonic acid ([1,1-D2]-AEP) is taken up from the growth medium by Acanthamoeba castellanii, diluted by material of de-novo biosynthesis and hydroxylated to OH-AEP. [2,2-D2]-AEP (18) is partly unchanged transformed into OH-AEP and partly to the monodeuterated AEP by enzymic exchange of D for H prior to hydroxylation. [2,2-D2]-AEP was prepared from 2-(benzyloxy)-[1,1-D2]ethanol (13). 2-Phthalimido-[1-D1]ethanol (20) was used as starting material for the synthesis of [1-D1]-AEP (23), which was also fed to the amoeba. The biosynthesis of OH-AEP occurs by direct hydroxylation of AEP with no isotope effect, and the oxygen of the hydroxy group is derived from the air.
    Notes: (2-Amino-l-hydroxyethyl)phosphonsäure (1) (OH-AEP) wurde in das kristalline Benzamid 11 übergeführt. (2-Amino-[1,1-D2]-ethyl)phosphonsäure ([1,1-D2]-AEP) wird von Acanthamoeba castellanii aus dem Nährmedium aufgenommen, durch Material der De-novo-Biosynthese verdünnt und zu OH-AEP hydroxyliert. [2,2-D2]-AEP (18) wird teils unverändert in OH-AEP übergeführt, teils durch enzymatischen Austausch eines D gegen H zuvor in monodeuteriertes AEP umgewandelt. [2,2-D2]-AEP wurde aus 2-(Benzyloxy)-[1,1-D2]ethanol (13) hergestellt. Für die Darstellung von [1-D1]-AEP (23), das ebenfalls an die Amöben verfüttert wurde, diente 2-Phthalimido-[1-D1]ethanol (20) als Edukt. Die Biosynthese von OH-AEP erfolgt durch direkte Hydroxylierung von AEP, wobei kein Isotopeneffekt beobachtet wird und der Sauerstoff der Hydroxylgruppe aus der Luft stammt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198819880608
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  • 10
    Electronic Resource
    Electronic Resource
    Biosynthese von Naturstoffen mit einer P—C-Bindung, IV. Synthese der (R)- und (S)-(2-Amino[2-D1]ethyl)phosphonsäure und Hydroxylierung zu (2-Amino-1-hydroxyethyl)phosphonsäure in Acanthamoeba castellanii (Neff) (1988)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1988 (1988), S. 961-964 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Biosynthesis of Natural Products with a P — C Bond, IV. - Synthesis of (R)- and (S)-(2-Amino-[2-D1]ethyl)phosphonic Acid and Hydroxylation to (2-Amino-1-hydroxyethyl)phosphonic Acid in Acanthamoeba castellanii (Neff)Starting from (S)-(+)-2-(benzyloxy)[1-D1]ethanol (3), (R)-(-)-and (S)-(+)-(2-amino[2-D1]ethyl)phosphonic acid (8) are prepared. The enantiomeric excess as determined by 1H-NMR spectroscopy after derivatisation with (+)-α-(methoxy)-α-(trifluoromethyl)phenylacetyl chloride is 98%. These [2-D1]-AEP are hydroxylated by Acanthamoeba castellanii to give (2-amino-1-hydroxy[2-D1]ethyl)phosphonic acids (OH-AEP) (2-D1-2). (S)-(+)-[2-D1]-AEP is transformed into (2S)-[2-D1]-OH-AEP, also obtained from [2,2-D2]-AEP besides [2,2-D2]-OH-AEP. Therefore, the pro-R deuterium of [2,2-D2]-AEP is partly exchanged by an aminotransferase.
    Notes: Ausgehend von (S)-(+)-2-(Benzyloxy)[1-D1]ethanol (3) wurden (R)-(-)- und (S)-(+)-(Amino[2-D1]ethyl)phosphonsäure (8) synthetisiert. Der Enantiomerenüberschuß wurde mittels 1H-NMR-Spektroskopie nach Derivatisierung mit (+)-α-(Methoxy)-α-(trifluormethyl)phenylessigsäurechlorid bestimmt und beträgt 98%. Von Acanthamoeba castellanii werden diese zur (2-Amino-1-hydroxy[2-D1]ethyl)phosphonsäure (OH-AEP) (2-D1-2) hydroxyliert. Aus (S)-(+)-[2-D1]-AEP entsteht dabei (2S)-[2-D1]-OH-AEP, die auch aus [2,2-D2]-AEP neben [2,2-D2]-OH-AEP entsteht. Eine Aminotransferase tauscht somit teilweise das pro-R-Deuterium der [2,2-D2]-AEP gegen Wasserstoff aus.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198819881005
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