Total synthesis of tricyclic β-lactams

Article abstract of DOI:10.1016/S0040-4020(98)01152-1

The synthesis of tricyclic carbapenam and penems was achieved by highly stereoselective Lewis acid-catalyzed reactions of 4-substituted 1- trimethylsilyloxyfurans with a 4-acetoxy azetidinone chiron, and further elaboration of the resulting condensation products using intramolecular Michael cyclizations.