合成路线1

3) The condensation of (4S,5R)-3-(bromoacetyl)-4-methyl-5-phenyloxazolidin-2-one (I) with benzaldehyde (II) by means of dibutylboron triflate gives intermediate (III), which by treatment with lithium ethoxide yields (R,R)-3-phenyloxirane-2-carboxylic acid ethyl ester (IV). The reaction of (IV) with sodium azide in ethanol affords the hydroxy ester (V), which is hydrogenated with H2 over Pd/C in ethyl acetate, giving the amino ester (VI). The protection of (VI) with tert-butoxycarbonyl anhydride affords the protected amino ester (VII), which is treated with 2-methoxypropene and pyridinium p-toluenesulfonate to give the oxazolidine (VIII). The hydrolysis of (VIII) with LiOH in ethanol/water yields (4S,5R)-3-(tert-butoxycarbonyl)-2,2-dimethyl-4-phenyloxazolidine-5-carboxylic acid (IX), which is condensed with the protected baccatin III (X) by means of dicyclohexylcarbodiimide (DCC) and DMAP to afford the oxazolidine ester (XI). The treatment of (XI) with formic acid gives the amino ester (XII), which is benzoylated with benzoyl chloride and NaHCO3 to the protected paclitaxel (XIII). Finally, this compound is deprotected by treatment with Zn/acetic acid. (Commercon, A. et al. Tetrahedron Lett 1992, 33(36): 5185).