Catalytic Asymmetric Synthesis of Macrocyclic (E)-Allylic Alcohols from ω-Alkynals via Intramolecular 1-Alkenylzinc/Aldehyde Additions

The ω-alkynals yielded macrocyclic (S)-allylic alcohols in a one-pot reaction sequence involving alkyne monohydroboration, boron to zinc transmetalation, and ((+)-DAIB)-catalyzed enantioselective intramolecular ring closure to the aldehyde function. A general study of this macrocyclization methodology is presented with respect to ligand type, size, and nature of the formed rings.