Methods for the preparation of taxanes using oxazolidine intermediates

A method for the preparation of a compound of the following formula VI or salt thereof:

• where
• R1 is hydrogen, arylcarbonyl, alkoxycarbonyl or alkylcarbonyl;
• R2 is aryl, heterocyclo or alkyl;
• and
• T is a taxane moiety directly bonded at C-13 of said moiety;
• comprising the steps of:
• (a) contacting a compound of the following formula III or salt thereof:
• where
• R1 and R2 are as defined above;
• and
• R5 and R6 are (a) each independently alkyl;
• or (b) together with the carbon atom to which they are bonded, form a cycloalkyl, cycloalkenyl or heterocyclo group;
• with a compound of the following formula IV or salt thereof:
• HO—T (IV),
• where T is as defined above, in the presence of a coupling agent, to form a compound of the following formula V or salt thereof:
• where R1, R2, R5, R6 and T are as defined above;
• and
• (b) contacting said compound of the formula V or salt thereof with a ring-opening agent, and, optionally, deprotecting one or more protected hydroxyl groups, to form said compound of the formula VI or salt thereof.