Patent ID: 7176326

Claim:
A method for the preparation of a sidechain-bearing taxane of the following formula VII or a salt thereof: where R 1 and R2 are: (i) both the same alkyl group; (ii) together form a cycloalkyl group; (iii) together form a cycloalkenyl group; or (iv) together form a heterocyclo group; R 3 is alkyl; R 4 is aryl; R 5 is hydrogen, arylcarbonyl, or alkyloxycarbonyl; and T is a taxane moiety bonded directly at C-13 of said moiety; comprising the step of contacting a β-lactam of the following formula I or a salt thereof: where R 1 , R 2 , R 3 , R 4 , and R 5 are as defined above with a taxane compound of the following formula VIII or a salt thereof: HO-T (VIII) where T is as defined above, in the presence of a coupling agent; and optionally converting the group —OC(R 1 )(R 2 )(OR 3 ) of said compound of the formula VII to hydroxyl, thereby forming a sidechain bearing taxane or a salt thereof of the following formula IX: where R 4 , R 5 , and T are as defined above.