10-deactyltaxol (10-deacetylpaclitaxel) is a naturally occurring taxane related to taxol (paclitaxel). Taxol is an antitumor drug with cytotoxic properties that correlate with its microtubule-stabilizing activities. When compared to paclitaxel 10-deacetyltaxol is 100% as active as paclitaxel in promoting in vitro microtubule assembly, but is only 30% as cytotoxic as paclitaxel. 10-deactyltaxol is a semi-synthetic precursor of paclitaxel and considered to be paclitaxel impurity. 10-deactyltaxol, isolated from the bark of Taxus brevifolia, was converted into paclitaxel in one composite step (trimethylsilylation, acetylation, and desilylation) and in an overall yield of 80-85%.