THE CHEMISTRY OF THE TAXANE DITERPENE - STEREOSELECTIVE SYNTHESIS OF 10-DEACETOXY-11,12-EPOXYPACLITAXEL

Epoxidation of the olefin in 10-deacetoxybaccatin III (6) and 10-deace toxypaclitaxel (9) was accomplished with meta-chloroperbenzoic acid le ading to a novel pentacyclic ring system. Hydroxyl directed delivery o f the epoxidizing agent did not appear to play a role in the stereosel ectivity of the reaction as epoxidation occurred at the beta-face of t he molecule, 10-Deacetoxy-11,12-epoxypaclitaxel (10) proved to be more active than paclitaxel (1) in the microtubule assembly assay and thre e-fold less cytotoxic than paclitaxel against B16 melanoma cells.