ISSN:
0075-4617
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Reactions of D-Glucuronic Acid, X. - Elimination Reactions of D-Glucofuranurono-6,3-lactone and its DerivativesIn the presence of bases D-glucofuranurono-6,3-lactone, its glycosides, and their 2,5-di-O-alkyl derivatives, respectively, form doubly unsaturated products. This reaction is initiated by proton abstraction at C-5 causing β-elimination with opening of the tetrahydrofuran ring and liberation of the aldehyde function. In a subsequent second elimination (2E, 4Z)-2,5-dihydroxy-and (2E, 4Z)-2,5-dialkoxy-6-oxo-2,4-hexadienoic acid, respectively, are formed, of which the former spontaneously isomerizes to the thermodynamically more stable (2Z, 4Z)-conformer.
Notes:
D-Glucofuranurono-6,3-lacton, seine Glykoside und deren 2,5-Di-O-alkylderivate reagieren mit Basen unter Bildung doppelt ungesättigter Produkte. Diese Reaktion wird durch Protonabstraktion an C-5 eingeleitet, wobei der Tetrahydrofuranring durch β-Eliminierung geöffnet und die Aldehydgruppe in Freiheit gesetzt wird. In der daran anschließenden Aldoleliminierung bilden sich (2E, 4Z)-2,5-Dihydroxy-oder (2E, 4Z)-2,5-Dialkoxy-6-oxo-2,4-hexadiensäure, von denen die erstere spontan zum thermodynamisch stabileren (2Z, 4Z)-Konformeren isomeriiert.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.197719770117
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