Total Synthesis of the Spliceosome Modulator Pladienolide B via Asymmetric Alcohol‐Mediated syn ‐ and anti ‐Diastereoselective Carbonyl Crotylation

Abstract The potent spliceosome modulator pladienolide B, which bears 10 stereogenic centers, is prepared in 10 steps (LLS). Asymmetric alcohol‐mediated carbonyl crotylations catalyzed by ruthenium and iridium that occur with syn ‐ and anti ‐diastereoselectivity, respectively, were used to form the C20‐C21 and C10‐C11 C−C bonds.