Intermediates for preparation of taxols
 A taxol intermediate selected from the group consisting of: ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and each selected from hydrogen, hydroxyl, or a protected hydroxyl; or R.sup.1 and R.sup.2 together form an oxo or a protected oxo; R.sup.3 is formyl, a protected formyl, or --CH(X)--OY wherein X is hydrogen or a monovalent metal and Y is hydrogen or a hydroxyl protecting group; and R.sup.4 and R.sup.5 are different and each selected from chloro or cyano; or R.sup.4 and R.sup.5 together form an oxo or a protected oxo, with the proviso that R.sup.1 and R.sup.2 are not both hydroxyl; R.sup.6 is hydroxyl or a protected hydroxyl; R.sup.7 is hydrogen, hydroxyl, or a protected hydroxyl; R.sup.8 is carboxyl, hydroxylmethyl, or a protected hydroxylmethyl; or R.sup.7 and R.sup.8 when taken together with carbon atoms 3 and 4, form an oxetane ring; or R.sup.6 and R.sup.8 when taken together with carbon atoms 1 and 4, form a bridged lactone; R.sup.9 is hydrogen or a hydroxyl protecting group; R.sup. 10 is hydroxyl or a protected hydroxyl; or R.sup.8 and R.sup.10 when taken together with carbon atoms 4 and 5, form a .gamma.-butyrolactone ring; R.sup.11 is alkoxycarbonyl, formyl, a protected formyl, hydroxylmethyl or a protected hydroxylmethyl; or R.sup.6 and R.sup.11 when taken together with carbon atoms 1 and 6, form a 2,2-dimethyl-1,3-dioxane ring; and the dotted line between the 2- and 3-positions of the six-membered ring represents an optional bond. 
Y C C C C C C C C
Y02P C07D C07D C07C C07F C07D C07C C07D C07C
additional inventional inventional additional inventional inventional inventional inventional inventional
Erik J. Jin-Jun Chan-Kou K. C.
Sorensen Liu Hwang Nicolaou