Enantioselective synthesis of oasomycin A, part I: Synthesis of the C1-C12 and C13-C28 subunits

Abstract

(Chemical Equation Presented) Putting the pieces together: The total synthesis of the natural macrolide oasomycin A has been realized. Key fragment couplings include an anti-Felkin selective aldol addition (green), Kociensky-Julia olefinations (red), and competitive Weinreb amide acylation reaction (blue). The utility of the 4,5-diphenyloxazole as a carboxy surrogate and the late-stage macrolactonization affording the 42-membered macrocycle of oasomycin A are also described. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.