ISSN:
0170-2041
Keywords:
Glycosides
;
Disaccharides
;
Undecaose
;
Carbohydrates
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
From 4-O-unsubstituted glucose derivatives 1a, b the 4-hydroxymethyl-substituted glucose derivatives 9a, b were obtained via oxidation to the ketone, Wittig reaction with methylenetriphenylphosphorane, borane addition, and subsequent oxidation to yield the diastereomeric galactose-derived compounds 5a, b; the required inversion of configuration at C-4 was accomplished through oxidation to the formyl derivatives, base-catalyzed isomerisation, and then reduction. Transformation of hydroxymethyl derivatives 9a, b into the iodo derivatives 11a, b and reaction with n-butyllithium generated the C-lithiated species 11aA, bA which furnished with O-benzyl-protected gluconolactone 12 the ketose derivatives 13a, b. Treatment with Et2O-BF3 afforded under concomitant 6-O-debenzylation the spiroketals 15a, b. Hydrogenolytic O-debenzylation and subsequent O-acetylation led to compounds 16a and 16b, respectively. The anomeric ketoside configuration was derived from NOE experiments.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199219920166
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