| 摘要 |
<p>The invention relates to O-substituted 7 beta -amino-3-cephem-3-ol-4-carboxylic acid compounds of the formula <IMAGE> (IA) wherein R1a represents hydrogen or an amino protective group R1A and R1b represents hydrogen or an acyl group Ac, or R1a and R1b together represent a bivalent amino protective group, R2 represents hydroxyl or a radical R2A which together with the carbonyl grouping -C(=O)- forms a protected carboxyl group and R3 represents an optionally substituted hydrocarbon radical or an acyl group, and to 1-oxides of 3-cephem compounds of the formula I, and also to the corresponding 2-cephem compounds of the formula <IMAGE> (IB) wherein R1a, R1b, R2 and R3 have the abovementioned meanings, or salts of such compounds with salt-forming groups. 3-Cephem compound of the formula IA, particularly those, in which R1a represents an acyl group, R1b is hydrogen and R2 is hydroxy exhibit pronounced antimicrobial effects, the others, and particularly the 1-oxides of these 3-cephem compounds and the corresponding 2-cephem compounds are useful as intermediates.</p> |
