Phenoxymethylpenicillin sulfoxide

Conceptually closely related, cefroxadi ne (40) can be prepared by several routes, including one in which the enol (33) is imethylated with diazomethane as a key step. A rather more involved route starts with comparatively readily available phenoxymethylpenicillin sulfoxide benzhydryl ester (36). This undergoes fragmentation when treated with benzothiazole-2-thiol to give Ozonolysis (reductive work-up) cleaves the... 

Cephalosporin (2).1 Reflux of phenoxymethylpenicillin sulfoxide methyl ester 1, with a trace of p-toluenesulfonic acid in xylene gave 2 (15%), mp 141-142°C, [Pg.251]

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