An efficient synthesis of 4(5),11(12)-taxadiene derivatives and microbial mediated 20-hydroxylation of taxoids

4(20),11(12)-Taxadiene 1 is specifically converted into 4(5),11(12)-taxadiene 5 via Claisen-like rearrangement and Barton radical desulfurization (cleavage of C–S bond) in high yield. Taxoid 5 and its deoxygenated derivatives are potential biosynthetic precursors of paclitaxel and other taxoids. 20-Hydroxylated metabolite 8 is one major product from microbially mediated hydroxylation of 5.