Enantioselective [2,3] Sigmatropic Rearrangement of α-Propargyloxyacetic Acids Mediated by BuLi-(-)-Sparteine Complex

The [2,3] sigmatropic rearrangement of α-propargyloxyacetic acids was achieved by the use of BuLi-(-)-sparteine complex in toluene. BuLi-chiral ligand complexes are stronger bases than lithium amides, so they are expected to be good mediators of this reaction.