ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Amphiphilic carbohydrate-based mesogens, V. Mesogenic 1-O-alkyl-D-glucitols from alkyl D-glucopyranosides (1990)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1990 (1990), S. 811-813 
    Details
    ISSN: 0170-2041
    Keywords: Liquid crystals ; 1-O-Alkyl-D-glucitols ; Glycoside hydroboration ; Carbohydrates ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The endocyclic acetal bonds of alkyl D-glucopyranosides (hexyl to decyl, 1a - e) are regioselectively hydroborated with ethyldiboranes(6) in the presence of 9-methylsulfonyloxy-9-borabicyclo[3.3.1]nonane (MSBBN) after conversion to their 2,3,4,6-tetra-O-diethylboryl derivatives 2a - e. Subsequent deboronations give the mesogenic 1-O-alkyl-D-glucitols 3a - e.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1990199001150
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Organoboron monosaccharides, XVI. Selective syntheses of the methyl α-D-furanosides of Lyxose and Mannose using ethyl(dimethoxy)borane (1990)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1990 (1990), S. 807-810 
    Details
    ISSN: 0170-2041
    Keywords: Ethyl(dimethoxy)borane ; O-Ethylboranediyl protection ; Methyl α-D-lyxo(or manno)furanosides ; Glycosidation ; Carbohydrates ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ethyl(dimethoxy)borane is prepared by a two-step method involving reaction of triethylboroxin with 1,4-butanediol in a molar ratio of 1:3 to give oligomeric 1,4-butanediyldioxy-ethylboranes which are then treated with methanol. D-Lyxose (1) reacts selectively with ethyl(dimethoxy)borane in the presence of acidic ion exchange resin to form methyl 2,3-O-ethylboranediyl-α-D-lyxofuranoside (2) which is deboronated to give methyl α-D-lyxofuranoside (4). Similarly, D-mannose (6) reacts to give methyl 2,3:5,6-bis-O-ethylboranediyl-α-D-mannofuranoside (7), the deprotection of which yields methyl α-D-mannofuranoside (8).
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1990199001149
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Amphiphilic carbohydrate-based mesogens, VIIDedicated to Professor Paul Binger on the occasion of his 60th birthday.. Synthesis of mesogenic 4- and 6-O-alkyl-D-glucitols (1991)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1991 (1991), S. 463-467 
    Details
    ISSN: 0170-2041
    Keywords: Liquid crystals ; Carbohydrates ; 4(6)-O-Alkyl-D-glucitols ; Acetal hydroboration ; Amphiphilic ethers ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Both the hemiacetal and acetal groups of 4,6-O-alkylidene-α/β-D-glucopyranoses (hexylidene-decylidene, 1a-e) are quantitatively reduced by ethyldiboranes(6) in the presence of 9-methylsulfonyloxy-9-borabicyclo[3.3.1]nonane (MSBBN) after conversion to their 1,2,3-tri-O-diethylboryl derivatives 2a-e. Subsequent deboronations give ca. 1:1 mixtures of 4-O-alkyl-D-glucitols 3a-e and 6-O-alkyl-D-glucitols 4a-e, which are separated to give mesogenic 3 and 4. Both 3 and 4 exhibit smectic A liquid crystalline phases.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199119910184
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Amphiphilic carbohydrate-based mesogens, VI. Synthesis of a series of alkyl 1-thio-D-glucopyranosides and their regioselective reductions to 1-alkylthio-1-deoxy-D-glucitols (1990)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1990 (1990), S. 1025-1027 
    Details
    ISSN: 0170-2041
    Keywords: Carbohydrates ; Liquid crystals ; 1-Thio-α,β-D-glucopyranosides ; Glucitol derivatives ; Glycoside hydroboration ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Alkyl 1-thio-α,β-D-glucopyranosides (hexyl to decyl, 1a-e) are prepared by reaction of penta-O-acetyl-β-D-glucopyranose with the respective thiols in the presence of diethyl ether  -  trifluoroborane, followed by deacetylation. 1a-e are converted into their tetra-O-diethylboryl derivatives 2a-e and reduced with ethyldiboranes(6) in the presence of the catalyst 9-methylsulfonyloxy-9-borabicyclo[3.3.1]nonane (9-BBN-mesylate, MSBBN) to give the mesogenic 1-alkylthio-1-deoxy-D-glucitols 3a-e after deboronation.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1990199001185
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Organoboron monosaccharides, XVIII. Stereoselective syntheses of β-D-lyxofuranosyl glycosides (1990)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1990 (1990), S. 1093-1096 
    Details
    ISSN: 0170-2041
    Keywords: Organoboron monosaccharides ; β-D-Lyxofuranosides ; Glycosides ; Carbohydrates ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Methyl and phenyl β-D-lyxofuranoside (3a and 3b) are prepared by reaction of 5-O-acetyl-2,3-O-ethylboranediyl-α-D-lyxofuranosyl bromide (1) with sodium methoxide and sodium phenoxide to give the protected glycosides 2a, b followed by deboronation and deacetylation. The protected α-D-lyxofuranosyl disaccharides 2c, d are synthesized by treatment of 1 with 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose and 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose after the former has been converted to its sodium organooxytriethylborate and the latter has been O-tributylstannylated. 2c and 2d are deboronated and deacetylated to give 3c and 3d, respectively. 2,3,5-Tri-O-acetyl-β-D-lyxofuranosyl glycosides (4a-d) are obtained from 3a-d by acetylation.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1990199001197
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Amphiphilic Carbohydrate-based Mesogens, IX. Mesogenic 4-O-Alkyl-D-glucoses via Methyl 4,6-O-Alkylidene-D-glucopyranosides (1993)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1993 (1993), S. 1063-1067 
    Details
    ISSN: 0170-2041
    Keywords: Carbohydrates ; 4-O-Alkyl-D-glucoses ; Liquid crystals, smectic ; Bromodiethylborane-sodium triethylhydroborate reducing system ; Amphiphilic glucoses ; X-ray diffraction, small angle ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 4,6-O-alkylidene derivatives (hexylidene-decylidene, 2a-e) are prepared by condensation of methyl α- or β-D-glucopyranoside 1 with alkanals in the presence of pyridinium tosylate. O-diethylborylation of 2 gives 3 which are allowed to react firstly with bromodiethylborane and subsequently with sodium triethylhydroborate to yield methyl 4-O-alkyl-D-glucopyranosides 5 after deborylation. Acid hydrolysis of 5 gives mesogenic 4-O-alkyl-D-glucopyranoses 6a-e. The amphiphilic 6 exhibit the smectic A liquid crystalline phase on melting.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1993199301171
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Synthesis of Carbon-Backbone-Elongated GDP-L-Fucose Derivatives as Substrates for Fucosyltransferase-Catalysed ReactionsDedicated to Professor Helmut Kristen. (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 601-612 
    Details
    ISSN: 0947-3440
    Keywords: Wittig reactions ; Amphiphiles ; L-Fucose analogues ; Nucleotides ; Fucosyltransferase ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Starting from the 6-O-tert-butyldimethysilyl-2,3;4,5-di-O-isopropylidene-D-galactose diethyl dithioacetal (4) and proceeding through a Wittig reaction and Swern oxidation, a series of L-fucose analogues, which unlike the normal L-fucose possess an extended alkyl-chain at C-5, can be produced. The elongated carbon backbone in the L-fucitols (22-25) as well as in the L-fucose derivatives (30-33) increases the hydrophobic nature of the sugar molecule, promoting liquid-crystalline properties in both series. The further derivatization of the L-fucose analogues 30, 31 leads to the corresponding β-L-galacto-deco- and dodeco-pyranosyl phosphates 46, 47 and, in turn, to the respective pyranosyl guanosine 5-diphosphates 48, 49. The reaction of the β-L-galactopyranosyl guanosine 5-diphosphate 48 with 8-methoxycarbonyloctyl 2-acetamido-2-deoxy-4-O-(β-D-galactopyranosyl)-β-D-glucopyranoside (50) in the presence of a 3/4-α-fucosyltransferase furnished an O-glycosidic linkage of the α-L-galactopdecopyranose 30 at the 3-O-position of the N-acetyllactosamine glycoside 50. The chemo-enzymatic coupling reaction proves that the synthesized carbon-backbone-elongated L-galactopyranosyl guanosine 5-diphosphates are suitable substrates for the α-fucosyltransferases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719970323
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    1-[1,7-dicarba-closo-dodecaboran(12)-1-yl]aldoses: Novel Boron Neutron Capture Candidates (1993)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1993 (1993), S. 831-835 
    Details
    ISSN: 0170-2041
    Keywords: Boron neutron capture therapy ; 1-[1,7-Dicarba-closo-dodecaboran(12)-1-yl]aldoses ; 1-[m-Carboran-1-yl]aldoses ; Boranes ; Carbohydrates ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monolithiated 1,7-dicarba-closo-dodecaborane(12) reacts with O-isopropylidene derivatives of D-erythrono-1,4-lactone (1), L-mannono-1,4-lactone (3) and with tetra-O-trimethylsilylated D-glucono-1,5-lactone (2) and D-gulono-1,4-lactone (4) to give the title compounds after deprotection. An X-ray structure analysis of the protected L-mannofuranose carborane derivative 9 reveals that the more stable anomer has the β-L configuration.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1993199301131
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Amphiphilic Carbohydrate-Based Mesogens, VIII. A Facile Synthetic Route to Mesogenic L-ribo-1,2,3,4-alkanetetrols (1992)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1992 (1992), S. 109-113 
    Details
    ISSN: 0170-2041
    Keywords: Liquid crystals ; Carbohydrates ; L-ribo-, D-lyxo-1,2,3,4-Alkanetetrols ; Wittig olefination ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Wittig olefinations of 2,3-O-isopropylidene-D-ribofuranose (1) with two equivalents of alkylidenetriphenylphosphorane (alkylidene: hexylidene  -  undecylidene) followed by hydrogenation catalyzed by palladium on carbon and subsequent deprotection yield (2R,3S,4S-(“L-”ribo)-1,2,3,4-alkanetetrols 5. These amphiphiles form the smectic A mesophase on melting. However, when 1 is heated with one equivalent of the alkylidenetriphenylphosphoranes for longer periods, (2R,3S,4R)-(“D-lyxo”)-1,2,3,4-alkanetetrol-type products 4 predominate.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199219920122
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...