title: Formation of enantiomeric 4-oxa-2,6-diazabicyclo(3.2.0)hept-2-en-7-ones from methyl 6alpha- and 6beta-phenoxyacetamidopenicillanates.
mesh_terms: D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis*; D001952:Bridged-Ring Compounds / Q000138:chemical synthesis*; D002700:Chloramines; D003508:Cycloheptanes / Q000138:chemical synthesis*; D007462:Iodobenzenes; D010404:Penicillin V / Q000031:analogs & derivatives*
chemical_list: D001643:Bridged Bicyclo Compounds; D001952:Bridged-Ring Compounds; D002700:Chloramines; D003508:Cycloheptanes; D007462:Iodobenzenes; D010404:Penicillin V