合成路线1

In an alternative procedure, paclitaxel (VII) was sequentially protected at the 2’ hydroxyl with tert-butyldimethylsilyl chloride and then at the 7-hydroxyl with triethylsilyl chloride, yielding the disilylated derivative (VIII). Selective hydrolysis of the C-2 benzoate and the C-4 acetate esters of (VIII) with Triton B afforded the triol (IX). Protection of the C-1 and C-2 hydroxy groups of (IX) with carbonyldiimidazole gave the 1,2-cyclic carbonate derivative (X). Subsequent treatment of (X) with methyl chloroformate and lithium bis(trimethylsilyl)amide introduced the 4-O-methoxycarbonyl group to furnish (XI). Opening of the cyclic carbonate group of (XI) with phenyllithium produced the benzoate ester (XII). The silyl protecting groups of (XII) were then removed by means of HF-pyridine.