Enantioselective total synthesis of ingramycin

An enantioselective total synthesis of the 14-membered macrolide antibiotic ingramycin, 1, is described. In a convergent approach three chiral fragments A,B and C are assembled, the allylic bromide A deriving its chirality from L-serine while the asymmetric centres in sulfones B and C are introduced via the Sharpless enantioselective epoxidation technique. After coupling of these fragments and a highly efficient macrolactonisation (82% yield) a final deprotection step furnishes the target compound.