Semisynthesis of Taxol : an improved procedure for the isolation of 10-deacetylbaccatin III

From the needles of domestic yew, (Taxus baccata), 10-deacetylbaccatin III (10-DAB) can be isolated in quantities of up to 297 mg per kg of fresh needles. Additional quantities of 10-DAB can be obtained from the extract by NaBH4 mediated reductive hydrolysis of baccatin esters. A four-step procedure converts 10-DAB into taxol in 58% overall yield.