An Efficient Construction of 4-Oxo-1, 3-diazabicyclo[3.3.0]octanes via Thiohydantoins

Abstract

New stereoisomeric N-bridged heterocycles, 4-oxo-1, 3-diazabicyclo-[3.3.0]octanes(4) were synthesized from trans-4-hydroxy-L-proline(1). Thiohydantoins 3 as the key intermediates were prepared by nucleophilic addition of 1 to isothiocyanates, and subsequent cyclization. These thiohydantoins 3 were readily desulfurized to provide 4.