a study of the published optical rotations and circular dichroic ( cd ) spectra of pentofuranosylpurines and of ( 6'-deoxy-beta-d-allo- and -alpha-l-talofuranosyl ) purines prepared here suggests that the sign of rotation and the sign of the longer wavelength cotton effect is determined solely by the configuration of c-1 ' and its position of attachment to the purine ring .
C0002144
allo
C0034140
purine