Studies on taxol biosynthesis.: Preparation of 5α-acetoxytaxa4(20),11-dien-2α,10β-diol derivatives by deoxygenation of a taxadiene tetra-acetate obtained from Japanese yew

The putative metabolite, 5alpha-acetoxytaxa-4(20),11-dien-2alpha,10beta-diol (7), which is a promising candidate as a biosynthetic pathway triol in taxol biosynthesis, has been prepared by Barton deoxygenation of the C-14-hydroxyl group of a differentially protected derivative of natural 2alpha,5alpha,10beta-triacetoxy-14beta-(2-methyl)-butyryloxytaxa-4(20),11-diene (8), a major taxoid metabolite isolated from Japanese 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. (C) 2002 Elsevier Science Ltd. All rights reserved.