Diazomethane → HCID 70604184, compound

Participants

Reaction Steps

More recently in my copending application Ser. No. 310,191 filed on Nov. 28, 1972 now U.S. Pat. No. 3,917,587 issued Nov. 4, 1974 the oxidation of 3-exomethylenecepham esters with ozone is described. The predominant product of the ozonolysis described therein is the 3-hydroxy-3-cephem ester which is reacted with a diazoalkene to provide the corresponding ester of a 3-alkoxy-3-cephem. Removal of the ester group provides the alkoxylated antibiotic compound. For example, 7-phenoxyacetamido-3-hydroxy-3-cephem-4-carboxylic acid p-nitrobenzyl ester, obtained by the ozonolysis of the corresponding 3-exomethylene compound, is reacted with diazomethane to form p-nitrobenzyl 7-phenoxyacetamido-3-methoxy-3-cephem4-carboxylate. The p-nitrobenzyl ester group is removed by catalytic hydrogenolysis in the presence of 5% palladium on carbon catalyst to provide the free carboxylic acid antibiotic compound. In the same application Ser. No. 310,191, the formation of 3-exomethylenecepham-4-carboxylic ester sulfoxides and 3-hydroxy-3-cephem-4-carboxylic acid ester sulfoxides are disclosed as side products of the ozonolysis reaction of 3-exomethylenecepham esters.

Provenance & Evidence