Studies on Taxol Biosynthesis: Preparation of Taxadiene-diol- and triol-Derivatives by Deoxygenation of Taxusin.

The putative taxol biosynthesis metabolites, taxa-4(20),11(12)-diene-5α, 13α -diol (7), taxa-4(20),11(12)-diene-5α, 9α, 13α-triol (9), and taxa-4(20),11(12)-diene-5α, 10β, 13α-triol (10), have been prepared by Barton deoxygenation of the C-9 and C10-hydroxyl groups of protected derivatives of taxusin, a major taxoid metabolite isolated from Yew heart wood. The synthetic protocol devised, is amenable for the preparation of isotopically labeled congeners that will be useful to probe further intermediate steps in the biosynthesis of taxol.