Abstract
Starting from 1-β-D-ribofuranosyl-2-oxo-4-imidazoline-4-carboxylic acid (1), obtained from uridine, various 2, 5'-O-cycloimidazole nucleosides have been prepared. The 2-oxo function of 1 was also converted to the 2-chloro and 2-thione functions. Whereas the circular dichroism (CD) spectra of 1 and related 2-oxo derivatives exhibited negative bands, their 5-bromo derivatives showed positive bands. All 2, 5'-O-cycloimidazole nucleosides showed strong negative CD bands which were in contrast to the results in the 8, 5'-O-cyclopurine nucleosides. The relationship between the sign of the CD bands and the orientation of the base moieties in imidazole nucleosides was discussed.
