| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the subject new compound having such a side chain that aβ-ketoester is put to ester linkage to a hydroxyl group on a specific site on the corresponding baccatine, and useful for preparing taxoid compounds such as paclitaxel as an anticancer agent. SOLUTION: This new compound is a compound of formula I [R1 and R2 are each a hydroxyl-protective group (e.g. triethylsilyl, benzyloxycarbonyl); R3 is a (substituted) phenyl, (substituted) furyl or the like; Bz is benzoyl], e.g. a compound of formula II. The compound of formula I is obtained by reaction of (A) a compound of formula III (e.g. 10-deacetylbaccatine III or an analog thereof) with (D) aβ-ketoester of formula IV (R4 is methyl, ethyl or the like) (e.g. methyl p-methoxybenzoylacetate, methyl m-fluorobenzoylacetate) in the presence of (B) a tin compound (e.g. 1-chloro-3-hydroxy-tetrabutyldistannoxane) or (C) an amine base (e.g. 4-dimethylaminopyridine).</p> |
