Oxidation of 2'-TBDMS-6 alpha-hydroxy-7-epipaclitaxel (1) with lead te
traacetate furnished 2'-TBDMS-C-norpaclitaxel (2) and the C-seco compo
und 3. Deprotection of 2 with pyridinium hydrofluoride yielded C-norpa
clitaxel (4). C-norpaclitaxel (4) is less effective at promoting the a
ssembly of microtubules and less cytotoxic towards HCT116 cells than p
aclitaxel.