| 摘要 |
<p>The present invention relates to a process for preparing paclitaxel represented by formula (1) characterized in that: (a) an oxazolidine derivative represented by formula (2) or its salt in which X represents halogen, is coupled with a 7-trihaloacetyl-baccatin III represented by formula (3) in which R1 represents trihaloacetyl, in a solvent in the presence of a condensing agent to produce an oxazolidine substituent-containing taxane represented by formula (4) in which X and R1 are each as previously defined; (b) the oxazolidine ring is opened in a solvent in the presence of an acid, and the product thus obtained is reacted with benzoyl chloride in the presence of a base to produce a protected paclitaxel wherein the hydroxy group at 7-position is protected with trihaloacetyl group represented by formula (5) in which R1 is as previously defined; (c) then the protecting group at 7-position is removed by ammonia or a salt of ammonia with a weak acid in a solvent.</p> |
