ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Nucleosides of Fluorine Carbohydrates. XV. Synthesis of Thymine Nucleosides of 6-Fluoro-D-glucopyranose and 6-Fluoro-D-galactopyranose1-β-D-glucopyranosyl thymine 1 and 1-β-D-galactopyranosyl thymine 13 react with equimolar amounts of tosyl or mesyl chloride to give predominantly the 6′-O-sulphonyl derivatives 6 and 7 or 14 and 15. Simultaneously small amounts of the 2′,6′-di-O-sulphonyl derivatives 4 and 5 are obtained. The tosyl derivative 6 reacts easily with alkali fluoride to give the 6′-deoxy-6′-fluoro nucleoside 10. In contrast to the glucose series the corresponding conversion of the 6′-sulphonyloxy-galactose derivatives is difficult to achieve.The condensation of 2,3,4-tri-O-acetyl-6-O-tosyl-D-glucopyranosyl bromide 2 or 6-deoxy-6-fluoro-1,2,3,4-tetra-O-acetyl-D-galactopyranose 18 with 2,4-bis-O-trimethylsilyl thymine 3 affords, after deacetylation, 6 and 1-(6′-deoxy-6′-fluoro-β-D-galactopyranosyl)thymine 20, respectively.
Notes:
1-β-D-Glucopyranosyl-thymin 1 und 1-β-D-Galaktopyranosyl-thymin 13 ergeben mit äquimolaren Tosyl-oder Mesylchlorid bevorzugt die entsprechenden 6′-O-Sulfonyl-Nucleoside 6 und 7 bzw. 14 und 15. In geringer Menge entstehen die 2′,6′-Di-O-sulfonyl-Derivate 4 und 5. Während in der Glucose-Reihe besonders die Tosylverbindung leicht mit Alkalifluorid zum 6′-Desoxy-6′-fluor-Nucleosid 10 reagiert, gelingt die analoge Substitution in der Galaktose-Reihe nur schwer.Die Kondensation 2,3,4-Tri-O-acetyl-6-O-tosyl-D-glucopyranosylbromid 2 bzw. von 1,2,3,4-Tetra-O-acetyl-6-desoxy-6-fluor-D-galaktose 18 mit 2,4-Bis-O-trimethylsilyl-thymin 3 führt zu Nucleosiden, die nach der Entacetylierung mit 6 bzw. 1-(6′-Desoxy-6′-fluor-β-D-galaktopyranosyl)-thymin 20 identisch sind.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19763180109
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