Stereocontrolled Synthesis of 1,5-Stereogenic Centers through Three-Carbon Homologation of Boronic Esters

Three more: The 3C homologation of chiral pinacol boronic esters gives di- or trisubstituted allylic boronic esters with high yield and E selectivities. The combination of this method with lithiation–borylation enables the synthesis of alkyl chains that bear 1,5-stereogenic centers. The utility of the process was demonstrated in a formal synthesis of (+)-jasplakinolide.