Organofluorine compounds and fluorinating agents. Part 11. Glycosyl fluorides from acetal-protected sugars

Miethchen, Ralf; Gabriel, T.

doi:10.1016/0022-1139(93)02938-b

Cited by 20 publications

(5 citation statements)

References 16 publications

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“…Here there is coupling with each other among the aliphatic protons of the anolic sodium methoxide had led to similar dimerisation products [34] . Here there is coupling with each other among the aliphatic protons of the anolic sodium methoxide had led to similar dimerisation products [34] .…”

Section: Methodsmentioning

confidence: 95%

ChemInform Abstract: Organofluorine Compounds and Fluorinating Agents. Part 19. Dithionite‐Catalyzed Addition of Perfluoroalkyl Iodides to Unsaturated Carbohydrates.

Zur

Miethchen

1998

ChemInform

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The perfluoroalkyl chains (ϪC 4 F 9 , ϪC 6 F 13 , ϪC 8 F 17 ) were ter-Compounds 9, 10, and 25 were hydrodeiodinated to the methylene derivatives 17, 18, and 27, respectively. Complete minally connected to the 5-enopyranose 1, and the 5-enofuranoses 8 and 23 by addition, in the presence of sodium dideprotection of the perfluoroalkyl-substituted pyranose 3 (prepared from 1), and of the furanoses 17 and 18 led to the thionite, of the corresponding homologous perfluoroalkyl iodides to the double bond. Up to six products were separated carbohydrate-based amphiphilic mesogens 29/30, 21, and 22, respectively, with a perfluoroalkyl tail. These formed mefrom each reaction mixture and then fully characterised. The 5-iodo derivatives 9, 10 (prepared from 8), 24, 25, and 26 sophases of the smectic A type. (prepared from 23) were diastereomeric mixtures (5R/5S). Fluorocarbons are biochemically inert, dense, have a lowWe tested several methods for the perfluoroalkylation of carbohydrates [20] with the aim of synthesizing a new group surface tension and have a very high gas dissolving capacity. For use as "artificial blood" for drug delivery and targeting, of "single tailed" amphiphilic liquid crystals. The most convenient, mild and inexpensive method seemed to be the diand for use as contrast agents, fluorocarbons have to be emulsified with water. For stable emulsions a variety of bio-thionite initiated addition of perfluoroalkyl halides to unsaturated compounds in water/acetonitrile [18] [19] , which compatible, strongly surface active fluorophilic/hydrophilic amphiphiles are needed. However, the higher the fluorine gave moderate and reproducible yields. The first applications of the dithionite initiation method in carbohydrate content of the amphiphile, the lower is its hemolytic activity [2] . Perfluoro-alkylated carbohydrates may serve as chemistry were reported by Portella and coworker [21] and Huang and coworkers [22] . We were unable to reproduce the useful emulsifiers for "water-in-fluorocarbon" emulsions intended for biomedical uses, such as drug targeting, because results of the latter; a perfluoroalkylation of triacetylglucal.Nearly no glucal reacted in the course of the reaction. Howtheir hydrophilic sugar head group may make them susceptible to recognition by specific receptors [3] [4] . In most of the ever, the addition of some perfluoroalkyl iodides to unsaturated monosaccharides with an exocyclic double bond in perfluoroalkyl-substituted carbohydrate amphiphiles which are already known, the perfluoroalkyl chain is attached to the 5-position did prove successful. Thus, the enopyranose 1 was reacted with perfluorohexyl iodide in the presence of the carbohydrate via a hydrocarbon spacer and an ester, ether, amide, or phosphate bond [4] [5] . In this paper we re-sodium dithionite to give a product mixture (compounds 2Ϫ7), where the perfluoroalkyl chain is regioselectively atport on the syntheses of carbohydrate-based perfluoroalkyl amphiphiles, where the perfluoroalkyl chain is directly at-tached to the 6-po...

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Section: Methodsmentioning

confidence: 95%

ChemInform Abstract: Organofluorine Compounds and Fluorinating Agents. Part 19. Dithionite‐Catalyzed Addition of Perfluoroalkyl Iodides to Unsaturated Carbohydrates.

Zur

Miethchen

1998

ChemInform

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“…We could show that a mixture from hydrogen fluoride, acetic acid anhydride and nitromethane allows the simultaneous realization of three reaction steps, i.e. acetal cleavage, acetylation and fluorination as a one pot reaction [24][25][26][27][28]. Examples of such Tandem-reactions are shown in Scheme 3.…”

Section: Anhydrous Hydrogen Fluoride/carboxylic Acid Anhydridementioning

confidence: 99%

“…The compounds 3, 5, 7 and 8 were directly transformed into the glycosyl fluorides 4, 6, and 9, respectively [24][25][26][27][28]. Undesired ring expansion of furanoses or contraction of pyranoses are completely suppressed.…”

Section: Anhydrous Hydrogen Fluoride/carboxylic Acid Anhydridementioning

confidence: 99%

Modified natural substances—fluorinated and fluoroalkylated monosaccharides and inositols

Miethchen

2004

Journal of Fluorine Chemistry

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“…Although acetyl hypofluorite has explosive character it has been used to good effect in organic and polymer chemistry by Rozen et al [34][35][36] CH 3 COOF has recently been used to fluorinate 1,2-dideoxyhexenofuranoses 15 and hexenofuranoses 17 [37,38].…”

Section: Bmentioning

confidence: 99%

Recent trends in the Chemistry of fluorinated five and six‐membered heterocycles

Erian

2001

Journal of Heterocyclic Chem

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Organofluorine compounds and fluorinating agents. Part 11. Glycosyl fluorides from acetal-protected sugars

Cited by 20 publications

References 16 publications

ChemInform Abstract: Organofluorine Compounds and Fluorinating Agents. Part 19. Dithionite‐Catalyzed Addition of Perfluoroalkyl Iodides to Unsaturated Carbohydrates.

ChemInform Abstract: Organofluorine Compounds and Fluorinating Agents. Part 19. Dithionite‐Catalyzed Addition of Perfluoroalkyl Iodides to Unsaturated Carbohydrates.

Modified natural substances—fluorinated and fluoroalkylated monosaccharides and inositols

Recent trends in the Chemistry of fluorinated five and six‐membered heterocycles

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