The first total synthesis of the potent RNA-polymerase inhibitor etnangien is described, which establishes unequivocally the relative and absolute configuration of this sensitive macrolide antibiotic. Key features of the expedient and modular synthesis include stereoselective substrate-controlled boron- and tin-mediated aldol couplings to set the characteristic sequences of methyl and hydroxyl bearing
A highlystereoselective joint total synthesis of the potent polyketide macrolide antibiotics etnangien and etnangien methyl ester was accomplished by a convergent strategy and proceeds in 23 steps (longest linear sequence). Notable synthetic features include a sequence of highlystereoselective substrate-controlled aldolreactions to set the characteristic assembly of methyl- and hydroxyl-bearing