- Semisynthetic ε-(iso)rhodomycins: a new glycosylation variant and modification reactions
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Synthesis of 7-O-(3-amino-2,3,6-trideoxy-α-L-lyxo-hexopyranosyl)-ε-(iso)rhodomycinones 16 and 17, and their 3'-morpholino derivatives are described.Glycosylation (trimethylsilyl triflate, 10:1 dichloromethane-acetone, -35 deg C) of 1-O-tert-butyldimethyls
- Kolar, Cenek,Kneissl, Guenther,Knoedler, Ursula,Dehmel, Konrad
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- C-DAUNOSAMINYL DERIVATIVES BY THE WITTIG REACTION
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C-Glycosylation of a 2-deoxypyranose has been achieved for the first time by conversion of 4-O-p-nitrobenzoyl-N-trifluoroacetyldaunosamine in a Wittig reaction into the corresponding derivative of ethyl 2-(daunosaminyl)acetate.The product was predominantly (54percent) in the desired α-L configuration (separated from the β-L anomer, 15percent) required for further elaboration of C-daunosaminyl derivatives.Conversion into the corresponding derivatives of 2-(α-L-daunosaminyl)acetaldehyde and 2-(α-L-daunosaminyl)ethanol was also achieved.
- Acton, Edward M.,Ryan, Kenneth J.,Smith, Thomas H.
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p. 235 - 246
(2007/10/02)
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- HEMISYNTHESE DE NOUVEAUX GLICOSIDES ANALOGUES DE LA DAUNORUBICINE
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Seven daunorubicin analogs containing α-L-, α-D-, and β-D-glicosidic linkages, in which the natural occuring sugar (L-daunosamine) was replaced by diastereomeric 3-amino-2,3,6-trideoxyhexoses (3-epi-L-daunosamine, D-acosamine, D-daunosamine, D-ristosamine, and 3-epi-D-daunosamine), were prepared.In all cases, glycosidation with daunomycinone was performed in the presence of p-toluenesulfonic acid starting from 1-O-acetyl-2,3,6-trideoxy-4-O-p-nitrobenzoyl-3-trifluoro-acetamidohexopyranoses (prepared from the corresponding methyl 3-amino-2,3,6-trideoxyhexopyranosides) or from 1,5-anhydro-2,3,6-trideoxy-4-O-p-nitrobenzoyl-3-trifluoroacetamidohex-1-enitols (prepared from glycosals or pseudoglycals, the 3-amino group being introduced by substitution with sodium azide and subsequent reduction).Glycosidation was followed by removal of the protecting groups.
- Boivin, Jean,Montagnac, Alain,Monneret, Claude,Pais, Mary
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p. 223 - 242
(2007/10/02)
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