Neue β-Lactam-Antibiotika. Zur Funktionalisierung von 3-Hydroxy-3-cephem-4-carbonsäureestern durch die Wittig-Reaktion. Modifikationen von Antibiotika. 16. Mitteilung [1]

New β-lactam antibiotics. Functionalisation of 3-hydroxy-3-cephem-4-carboxylic esters through the Wittig reaction The 3-hydroxy-ceph-3-em-esters 1a, b reacted smoothly with stabilized phosphor-ylids to give a series of derivatives which were converted into the microbiologically active acids 14a, c, 15c and 20 by known procedures. The synthesis of the amides 23, 24, 26 and of the ester 28 from the 3-carboxymethyl-derivative 19 is also reported.