A multistep stereospecific synthesis of two novel pyrazole C-nucleosides 12 and 21 has been achieved starting from D-glucose, by utilizing the 2,5-anhydro-D-glucose ethylene acetal derivative 1 as a divergent intermediate. The C-nucleoside 12 was shown to be a moderate inhibitor of the in vitro growth of N2a and BHK 21 tumor cell lines, whereas 21 showed a moderate cytotoxic activity only against N2a cells. (C) 2000 Published by Elsevier Science Ltd.