A number of 2'-oxycarbonylpaclitaxels (paclitaxel-2'-carbonates) 3 have been prepared and evaluated for their cytotoxicity and in vivo antitumor activity. Most of these paclitaxel-2'-carbonates were found to exhibit in vivo antitumor activity in the i.p. M109 murine tumor model system, comparable to that of the parent drug.