Total and Formal Syntheses of Fostriecin.

Two formal syntheses and one total synthesis of fostriecin () have been achieved, as well as, the synthesis of its related congener dihydro-dephospho-fostriecin. All the routes use the Sharpless dihydroxylation to set the absolute stereochemistry at -8/9 positions and a Leighton allylation to set the -5 position of the natural product. In the formal syntheses a Noyori transfer hydrogenation of an ynone was used to set the -11 position while the total synthesis employed a combination of asymmetric dihydroxylation and Pd-π-allyl reduction to set the -11 position. Finally in the total synthesis, a trans-hydroboration of the -12/13 alkyne was used in combination with a Suzuki cross coupling to establish the ,,-triene of fostriecin ().