| Abstract: | New β-lactam antibiotics. Functionalisation of the cephem 3-position with sulfur or nitrogen bearing substituents The 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. |
