A simple synthesis of (±)-1-carbacephem derivatives

Article abstract of DOI:10.1016/S0040-4039(00)94020-6

The Dieckmann condensation of the phenylthioester of 4-(1-t-butoxycarbonylmethyl-3-phenoxyacetamido-azetidin-2-one-4-yl)butylic acid affords a simple route to 3-substituted-8-oxo-7-phenoxyacetamido-1-azabicyclo[4,2,0]oct-2-ene-2-carb oxylic acids.