合成路线1

The reaction of (2R,3S)-phenylisoserine (I) with 2-propynyl chloroformate (II) in aq. NaHCO3 gives the N-acylated compound (III), which is treated with diazomethane in ethyl ether (CDI and methanol) to yield the corresponding methyl ester (IV). The reaction of (IV) with 2-methoxypropene (V) and pyridinium p-toluenesulfonate in toluene affords the oxazolidine (VI), which is treated with LiOH in water to provide the oxazolidine-5-carboxylic acid (VII). The esterification of 7-O-(trichloroethoxycarbonyl)baccatin (VIII) with acid (VII) by means of DCC in toluene gives the corresponding ester (IX), which is treated with ammonium tetrathiomolybdate to cleave the oxazolidine ring and yield the 3-amino-2-hydroxypropionyl ester (X). The reaction of (X) with benzoyl chloride (XI) and NaHCO3 in ethyl acetate affords the expected benzamido derivative (XII), which is finally deprotected by means of Zn and AcOH to afford the target paclitaxel.