2,9,10,13-tetradesacetyl-1,2-O-benzylidene-7-desacetoxy-9,10-O-isopropylidene-13-oxo baccatine IV

((2S,3aS,5S,7aR,10aR,10bR,14S,14aR,14bS)-5,14-dihydroxy-6,9,9,10b,15,15-hexamethyl-2-phenyl-5,7a,10a,10b,11,12,13,14,14a,14b-decahydro-4H-3a,7-methanobenzo[3,4]cyclodeca[1,2-d:5,6-d']bis([1,3]dioxole)-14-yl)methyl acetate

1,2-O-benzylidene-9,10-O-isopropylidene-4,20-dihydro-4α,20-dihydroxy-20-O-terbutyldimethylsilyl-5-O-mesyl taxicine I