674 research outputs found
The Beilstein Journal of Organic Chemistry and the changing face of scientific publishing
Acylsulfonamide safety-catch linker : promise and limitations for solid-phase oligosaccharide synthesis
Safety-catch linkers are useful for solid-phase oligosaccharide synthesis as they are orthogonal to many common protective groups. A new acylsulfonamide safety-catch linker was designed, synthesized and employed during glycosylations using an automated carbohydrate synthesizer. The analysis of the cleavage products revealed shortcomings for oligosaccharide synthesis
Casenotes: Attorney Conduct — a Defense Attorney Who Follows ABA Standards When His Client Manifests an Intent to Commit Perjury Is Not Jeopardizing the Client\u27s Right to Effective Assistance of Counsel. Nix v. Whiteside, 475 U.S. 157 (1986)
Casenotes: Attorney Conduct — a Defense Attorney Who Follows ABA Standards When His Client Manifests an Intent to Commit Perjury Is Not Jeopardizing the Client\u27s Right to Effective Assistance of Counsel. Nix v. Whiteside, 475 U.S. 157 (1986)
LUMBOVERTEBRAL SYNDROME AFTER EXTRADURAL BLOOD PATCH
SUMMARY We describe a patient who developed an immobilizing lumbovertebral syndrome after an extradural blood patch and who was hospitalized with a. suspected extradural abscess. An infectious aetiology of the persistent backache could be excluded and the patient recovered with analgesics and physiotherapy. The probable aetiology is discusse
Automated access to well-defined ionic oligosaccharides
Ionic polysaccharides are part of many biological events, but lack structural characterisation due to challenging purifications and complex synthesis. Four monosaccharides bearing modifications not found in nature are used for the automated synthesis of a collection of ionic oligosaccharides. Structural analysis reveals how the charge pattern affects glycan conformation
Visible-light-mediated Achmatowicz rearrangement
Visible-light-mediated photoredox catalysis is a viable method to access highly reactive intermediates from cheap, readily available, and shelf-stable reagents to perform clean chemical transformations. Here, we report the first photoredox-catalyzed Achmatowicz reaction of furfuryl alcohol derivatives to produce functionalized dihydropyranones while only forming easily separable NaHSO4 as a byproduct. The water solubility of the byproduct facilitates direct Boc-protection of the resulting hemiacetal without the need for column purification. The reaction is very robust and permits the use of various aqueous solutions and light sources including sunlight
Automated assembly of starch and glycogen polysaccharides
Polysaccharides are Nature’s most abundant biomaterials essential for plant cell wall construction and energy storage. Seemingly minor structural differences result in entirely different functions: cellulose, a β (1–4) linked glucose polymer, forms fibrils that can support large trees, while amylose, an α (1–4) linked glucose polymer forms soft hollow fibers used for energy storage. A detailed understanding of polysaccharide structures requires pure materials that cannot be isolated from natural sources. Automated Glycan Assembly provides quick access to trans-linked glycans analogues of cellulose, but the stereoselective installation of multiple cis-glycosidic linkages present in amylose has not been possible to date. Here, we identify thioglycoside building blocks with different protecting group patterns that, in concert with temperature and solvent control, achieve excellent stereoselectivity during the synthesis of linear and branched α-glucan polymers with up to 20 cis-glycosidic linkages. The molecules prepared with the new method will serve as probes to understand the biosynthesis and the structure of α-glucans
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