ASYMMETRIC WITTIG SIGMATROPIC REARRANGEMENT INVOLVING A CHIRAL AZAENOLATE AS THE MIGRATING TERMINUS. A SIMPLE SYNTHESIS OF (+)-VERRUCARINOLACTONE
The diastereo- and/or enantioselection are described in the title rearrangement of the chiral 2-(2-alkenyloxy)methyl 2-oxazolines which eventually provides optically active α-hydroxy γ,δ-unsaturated esters and (+)-verrucarinolactone.