CRYSTALLOGRAPHIC STUDY OF SOME PYRIMIDE NUCLEOSIDE ANALOGS, ACETYL DERIVATIVES OF BETA-D-GLUCOPYRANOSYLBENZENE AND BETA-D-MANNOPYRANOSYLBENZENE

The structures of the two title C-glycopyranosylarene nucleosides have been determined by X-ray diffraction. The aim of this work was to rel ate the conformation around the extracyclic C-1-C-7 bond to steric hin drance between the pyranose and benzene rings. The torsion angles obse rved in the two compounds (0-5-C-1-C-7-C-8: + 61,7-degrees for 1, - 13 ,4-degrees for 2) signify of a C-2 configurational modification. Moreo ver, the interaction between 0-5 and an o-phenyl hydrogen could explai n the particular conformation of the aryl substituent in 2.