A PRACTICAL, ENANTIOSELECTIVE SYNTHESIS OF SK-AND-F 104353

A highly efficient and enantioselective (>99.5% ee) synthesis of the t itle compound has been accomplished. Key steps include (1) epoxidation of unsaturated ketone 7 in the presence of a polyamino acid to afford compound 8 in >95% ee, (2) regioselective Baeyer-Villiger rearrangeme nt of epoxy ketone 8 to afford glycidic ester 9, and (3) regioselectiv e (35:1) opening of lithium glycidate 13 at C-3 with methyl 3-mercapto propionate. The approach is economical, and all transformations procee d in high yield and are amenable to large-scale preparation.