text: As shown in Scheme 1, the first steps in the synthesis created the bicyclo[5.3.1]undecane AB ring system of Taxol. Reaction of epoxide 1 with tert-butyllithium removed the acidic α-epoxide proton, leading to an elimination reaction and simultaneous ring-opening of the epoxide to give allylic alcohol 2. The allylic alcohol was epoxidized to epoxyalcohol 3 using tert-butyl hydroperoxide and titanium(IV)tetraisopropoxide. In the subsequent reaction, the Lewis acid boron trifluoride catalyzed the ring opening of the epoxide followed by skeletal rearrangement and an elimination reaction to give unsaturated diol 4. The newly created hydroxyl group was protected as the triethylsilyl ether (5). A tandem epoxidation with meta-chloroperbenzoic acid and Lewis acid-catalyzed Grob fragmentation gave ketone 6, which was then protected as the tert-butyldimethylsilyl ether 7 in 94% yield over three steps.