Chiral oxazolidinones as electrophiles: intramolecular cyclization reactions with carbanions and preparation of functionalized lactams

The intramolecular cyclizations of chiral oxazolidinones with carbanions adjacent to sulfones, sulfoxides, and phosphonates proceeds in excellent yields to obtain functionalized γ and δ lactams. The lactams from this study are useful synthetic intermediates, as demonstrated by the synthesis of a precursor for levetiracetam, an antiepileptic drug.