Use of an iodonium ylide in the synthesis of p-nitrobenzyl (6R, 7S) 3-hydroxy-8-oxo-7-phenoxyacetamino-1-azabicyclo[4.2.0]octa-2-ene-2-carboxylate

Abstract p-Nitrobenzyl (6R,7S)-3-hydroxy-8-oxo-7-phenoxyacetamido-1-azabicyclo [4.2.0]octa-2-ene-2-carboxyate ( 6 ) was synthesized utilizing rhodium(II)- or acid-catalyzed cyclization of iodonium ylide ( 5 ). The iodonium ylide ( 5 ) was easily prepared from the corresponding β-keto ester ( 4 ) and [(diacetoxy)iodo]benzene in good yield.