Neaumycin B is a femtomolar inhibitor of U87 human glioblastoma. Using a newly developed antidiastereoselective ruthenium-catalyzed butadiene-mediated crotylation of primary alcohol proelectrophiles via hydrogen auto-transfer, as well as a novel variant of the catalytic asymmetric vinylogous Mukaiyama aldol (VMA) reaction applicable to linear aliphatic aldehydes and terminally methylated dienyl ketene acetals, preparation of the key C1-C19 and C23-C35 substructures of neaumycin B is achieved in 12 and 7 steps (LLS), respectively.

Neaumycin B is a femtomolar inhibitor of U87 human glioblastoma. Using a newly developed anti‐diastereoselective ruthenium‐catalyzed butadiene‐mediated crotylation of primary alcohol proelectrophiles via hydrogen auto‐transfer, as well as a novel variant of the catalytic asymmetric vinylogous Mukaiyama aldol (VMA) reaction applicable to linear aliphatic aldehydes and terminally methylated dienyl ketene acetals, preparation of the key C1–C19 and C23–C35 substructures of neaumycin B is achieved in 12 and 7 steps (LLS), respectively.