Chair interconversion and reactivity of mannuronic acid esters
نویسندگان
چکیده
منابع مشابه
Chair interconversion and reactivity of mannuronic acid esters.
Mannopyranosyluronic acids display a very unusual conformation behavior in that they often prefer to adopt a (1)C4 chair conformation. They are endowed with a strikingly high reactivity when used in a glycosylation reaction as a glycosyl donor. To investigate the unusual conformational behavior a series of mannuronic acid ester derivatives, comprising anomeric triflate species and O-methyl glyc...
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The widespread occurrence of amino derivatives of the sugars in products of plant and animal origin suggests the possibility that amino derivatives of the uronic acids may likewise be of importance. The uronic acids have the characteristic structures of both aldoses and aldonic acids, and hence, like the aldoses, might be expected to yield glycosyl amines [1] and like the lactones of the aldoni...
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Interconversion of carbon sites in boat-chair-boat (BCB) cyclodecane occurs by way of the twist-boat-chair (TBC) conformation, which predicts that C-1 exchanges with C-4, etc. The previously obtained low-temperature 13C spectra could be matched by assuming (1,4) or (1,3) exchange, but not (1,2) exchange. A free-energy barrier of 5.54 kcal/mol was obtained for conversion of BCB to TBC at -137.4 ...
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ژورنال
عنوان ژورنال: Organic & Biomolecular Chemistry
سال: 2013
ISSN: 1477-0520,1477-0539
DOI: 10.1039/c3ob41747f