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-deacetoxypaclitaxel (9) was accomplished with meta-chloroperbenzoic acid leading to a novel pentacyclic ring system. Hydroxyl directed delivery of the epoxidizing agent did not appear to play a role in the stereoselectivity of the reaction as epoxidation occurred at the beta-face of the molecule, 10-Deacetoxy-11,12-epoxypaclitaxel (10) proved to be more active than paclitaxel (1) in the microtubule assembly assay and three-fold less cytotoxic than paclitaxel against B16 melanoma cells.