Stereo-controlled synthesis of prelasalocid, a key precursor proposed in the biosynthesis of polyether antibiotic lasalocid A

In the biosynthesis of a polyether ionophore antibiotic, lasalocid A, the cyclic ether skeleton composed of a tetrahydrofuran linked to a tetrahydropyran could be constructed by oxidative cyclization of linear dodecaketide diene precursor. Hence, we hypothesized a prelasalocid having (E,E)-trisubstituted olefins as the dodecaketide biosynthetic precursor. A stereo-controlled synthetic route to the prelasalocid has been devised in a highly convergent manner entailing installation of a variety of substituents at the trisubstituted olefins.