ISSN:
1572-8854
Keywords:
Nucleoside
;
hydrated nucleoside
;
anomeric differences
;
pyrimidine
;
uracil
;
xylofuranosyl ring
;
isopropylidene rings
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract 5-Acetyl-1-(3,5-O-isopropylidene-α-D-xylofuranosyl) uracil monohydrate (α-AXU·H2O) crystallizes in an orthorhombic cell of dimensionsa=7.286(6),b 14.281(10),c=15.852(11) Å. Its structure has been determined by direct methods from single-crystal CuK α X-ray data and refined to a conventionalR factor of 0.055 over 1708 unique reflections. The furanose ring has conformation C2'endo-C3'endo (rather than the uncommon C3'endo-C4'exo as in β-AXU) and the glycosidic torsion angle is −31° (17° in β-AXU). The oxygen of the water molecule in α-AXU·H2O accepts a hydrogen bond (O 10...O 5=2.70 Å) from the sugar hydroxyl O5 and the hydrogens form hydrogen bonds to a uracil carbonyl (O 10...O 2=2.78 Å) and an isopropylidene oxygen atom (O 10...O 7=2.90 Å).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01665987
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