Stereoselective Synthesis of Quaternary Pyrrolidine-2,3-diones and β‑Amino Acids

A facile, diastereoselective
synthesis of highly substituted pyrrolidine-2,3-diones
is reported, along with the one-step conversion of these heterocycles
to novel β-amino acids and further functionalized derivatives.
This method involves an unusually mild, one-pot, three-component cyclization/allylation
followed by a Claisen rearrangement to provide unusual pyrrolidinone
products that are densely functionalized and contain an all-carbon
quaternary stereocenter. The reported reaction sequence is operationally
simple, exquisitely diastereoselective, and provides gram-scale access
to valuable heterocyclic scaffolds and β-amino acids not readily
accessible via existing approaches.