Ruthenium‐Catalyzed Butadiene‐Mediated Crotylation and Oxazaborolidine‐Catalyzed Vinylogous Mukaiyama Aldol Reaction for The Synthesis of C1–C19 and C23–C35 of Neaumycin B
Xinting Liang, Minjin Yoo, Tabitha T. Schempp, Saki Maejima, Michael J. Krische
Abstract
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.
Topics & Concepts
Aldol reactionChemistryKeteneCatalysisRutheniumStereochemistryCombinatorial chemistryOrganic chemistryAsymmetric Hydrogenation and CatalysisSynthetic Organic Chemistry MethodsChemical Synthesis and Analysis