ISSN:
0170-2041
Keywords:
Carbohydrates
;
Trichloroacetimidates
;
Azidosphingosines
;
Glycosphingolipids
;
Enzyme inhibitors
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
D-Glucose was transformed into the 4-deoxy-4-C-methylene derivative 1. Dihydroxylation of 1 and then selective O-tosylation afforded 4-C-(tosyloxymethyl)glucoside 3. Subsequent hydrogenolytic O-debenzylation, selective O-acetylation, treatment with a base, selective removal of the anomeric O-acetyl group, and then treatment with trichloroacetonitrile in the presence of a base furnished 4-epoxy-4-C-methyleneglucosyl donor 7 (α,β mixture). Reaction of 7 with 3-O-acyl-protected azidosphingosines 8a-c in the presence of Et2O.BF3 gave β-glycosides 9a-c. Compounds 9a-c were transformed into the corresponding glucosylceramide derivatives 10a-c by treatment with triphenylphosphane/water and acyl anhydrides. Satisfactory removal of the O-benzoyl protective group was difficult; however, O-acetyl and O-isobutyryl protective groups could be removed by methanolysis, thus affording from 10b, c the target molecules 11 and 12 with varying alkyl-chain length. The epoxide 16 with galacto configuration, readily obtained from 1, on treatment with p-toluenesulfonic acid furnished 4-C-(tosyloxymethyl)galactoside 18; this was transformed, as outlined for 3, into the target molecules 25b, c having galacto configuration in the sugar moiety.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.1992199201118
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