Total synthesis of (-)-tirandamycin C

Tirandamycin C is a newly isolated member of the tetramic acid family natural products. We described herein the first enantioselective synthesis of natural (-)-tirandamycin C, the postulated biosynthetic precursor of other members of this family. The highly stereoselective (>15:1) mismatched double asymmetric γ-stannylcrotylboration reaction of aldehyde 8 with crotylborane reagent (R)-E-9 was utilized to access the key anti,anti-stereotriad 18.