3‑Diazopiperidine-2,4-diones\nas Convenient\nPrecursors to Rare Polysubstituted Spiro Bis-β,γ-lactams\nand 2‑Oxopyrrolidine-3-carboxylic Acid Derivatives via the\nThermally Promoted Wolff Rearrangement

Herein,\nwe describe a diastereoselective and straightforward synthetic\napproach to polysubstituted spirocyclic bis-lactams bearing both β-\nand γ-lactam cores with diverse substitution patterns. The method\ndeveloped is based on a microwave-assisted Wolff rearrangement/Staudinger\n[2 + 2] cycloaddition sequence involving 3-diazopiperidine-2,4-diones\nand imines. The corresponding reaction tolerates a wide range of functionalities\nin both substrates, giving the target bis-lactams in generally high\nyields. The synthetic utility of the thermally promoted Wolff rearrangement\nhas been extended to the interaction of 3-diazopiperidine-2,4-dione-derived\nketenes with various nucleophiles leading to derivatives of 2-oxopyrrolidine-3-carboxylic\nacids. Our findings potentially pave an avenue for designing new compounds\nwith a high degree of medicinal relevance by means of the processes\nstudied.