V. Fehring et al., A novel stereo-controlled nucleobase exchange process for the synthesis of2 '-C-branched nucleosides, J CHEM S P1, (19), 2000, pp. 3185-3187
A novel stereo-controlled process is described which enables the uracil bas
e on a 2'-deoxy-2'-alpha-C-carboxymethyluridine nucleoside to be exchanged
for either a purine or another pyrimidine base, via the intermediacy of an
isolable pentofuranosyl butyrolactone.