Process for cephalosporin antibiotic intermediates

摘要

7-Acylamido-3-exomethylenecepham ester sulfoxides are reacted with ozone to provide the corresponding 3-hydroxy-3-cephem ester sulfoxides, intermediates for 3-methoxy and 3-halo substituted cephalosporin antibiotics; e.g., p-nitrobenzyl 7-phenoxyacetamido-3-exomethylenecepham-4-carboxylate-1-oxide provides the corresponding 3-hydroxy-3-cephem ester sulfoxide.