Patent ID: 7232916

Claim:
A process for the preparation of 13-(N-Boc-β-isobutylserinyl)-14-β-hydroxybaccatin III-1,14-carbonate (I) which comprises the following steps: a) acetylation of the 10-hydroxy group of 14β-hydroxy-10-desacetylbaccatin III (IV) b) reaction of (V) with bis(trichloromethyl)carbonate to afford the 1,14 carbonate derivative (VI) c) reaction of (VI) with trichloroacetyl chloride to afford (VII) d) reaction (VII) with (4S,5R)-N-Boc-2-(2,4-dimethoxyphenyl)-4-isobutyl-1-oxazolidine-5-carboxylic acid, to afford (VIII) e) removal of the protective trichloroacetyl group with alkali from compound (VIII) f) removal of the dimethoxybenzylidene protective group from compound (IX)