| 摘要 |
<p>NEW MATERIAL:Optically active cephalosporin analogs of formula I (R1 is H, substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, acyl; R2 is H, lower alkyl; R3 is H, ester rediue; the configuration between hydrogen atoms between the 6 and 7 position is cis; OR1 is in syn position.) and their salts. EXAMPLE:( + )-7-[ 2-( 2-Amino-4-thiazolyl )-2-syn-methoxyiminoacetamide ]- 1-azabicyclo[4.2.0]oct-2-ene-8-one-carboxylic acid. USE:Antibiotic; they have strong antibacterial activity. PREPARATION:An optically active cephalosporin derivative of formula II is acylated with a reactive derivative of carboxylic acid shown as formula III (X is H, amino- protecting group) and protecting groups are removed from the resulting product of formula IV to give the objective compound of formula V.</p> |
