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Neue β‐Lactam‐Antibiotika. Cephem‐Derivate mit elektronenanziehenden Substituenten in 3‐Stellung. Modifikationen von Antibiotika. 14. Mitteilung
Author(s) -
Peter Heinrich,
Müller Beat,
Bickel Hans
Publication year - 1975
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19750580825
Subject(s) - cephem , chemistry , cephalosporin , lactam , stereochemistry , ring (chemistry) , antibiotics , polar effect , medicinal chemistry , organic chemistry , carboxylic acid , biochemistry
New β‐lactam antibiotics. Cephem derivatives with electron withdrawing substituents at position 3 Oxidation of the 3‐formyl‐2‐cephem compound 1 according to Corey [6] gave 2‐cephem‐3‐carboxylic esters 4a, b, c ( Scheme 1) , which proved to be useful intermediates for the synthesis of cephalosporins bearing in position 3 a methoxycarbonyl group (10a, b, c, d / Scheme 2) or a carboxy group (20, 25, 30/Schemes 3, 4). The 3‐formyl‐3‐cephem compounds 31a, b could be transformed into cyano‐ (33a) or methoxyiminomethyl‐ (36a, c, d) cephems (Scheme 5), which represent further examples of cephalosporins with electron withdrawing groups in position 3.