Neue ?-Lactam-Antibiotika. �ber die Funktionalisierung der Cephem-3-Stellung mittels Schwefel oder Stickstoff. Modifikationen von Antibiotika, 13. Mitteilung
New β‐lactam antibiotics. Functionalisation of the cephem 3‐position with sulfur or nitrogen bearing substituentsThe tosylate sulfoxides or mesylates derived from the 3‐hydroxy‐ceph‐3‐em esters 1a, b reacted with thiols to give 3‐thioethers which were converted into the microbiologically active acids 7a, c, 8a, c 9c, and 13c by known procedures. The 3‐methylsulfonyl‐derivative 17c was prepared from 6b. The synthesis of the 3‐acylamino‐ceph‐3‐em‐4‐carboxylic acids 23c and 24c is reported.