Synthesis of Fostriecin and 8-epi-Fostriecin

Significance

Fostriecin is a cytotoxic antibiotic isolated from Streptomyces pulveraceus. A synthetic route to fostriecin and 8-epi-fostriecin is reported in which all four stereocenters are installed using catalytic asymmetric methods. An enantio­selective cyanosilylation protocol developed within the group was employed to form the C-8 stereo­center in C. Both enantiomers were synthesized with high enantioselectivity by changing the metal of the catalyst from titanium to gadolinium thus allowing the synthesis of both Fostriecin and 8-epi-Fostriecin.