The imine 9, prepared by condensation of benzalehyde with benzylamine reacted stereospecifically with 2-acetoxyketene, prepared by 2-acetoxy acetyl chloride and triethylamine in situ to give 3-acetoxy-N-benzyl-4-phenyl-2-azetidinone (10). The bezylamino group in the molecule 10 ws oxidized to benzoyl amide 8 by chromium trioxide in acetic acid solution. Ring-openning of 8 with methanol in the presence of potassium carbonate produced taxol side chain methyl ester, methyl N-benzoyl-2-amino-3-hydroxy-3-phenyl-propionate (12). In order to esterification of 7-protected baccatin Ⅲ with the taxol side chain, the compound 12 was converted into acetonide 13, which hydrated to free acid, target molecule taxol side chain acetonide 5 with lithium hydroxide.

Key words: HYDROLYSIS, LACTAM, SIDE CHAIN, ACETONE P, TAXUS CHENSIS