| 摘要 |
<p>NEW MATERIAL:Optically active cephalosporin analogs of formula I (R1 is H, alkyl, alkenyl; R2 is H, lower alkyl, lower acyl; R3 is H, ester residue; the H atoms on the 6 and 7 positions are in cis and OR1 is insyn) and their salts. EXAMPLE:( 4S,6R,7S )-7-[2-(2-Amino-4-thiazolyl)-2-syn-methoxyiminoacetamide]- 4-hydroxy-1-azabicyclo[4,2,0]oct-2-ene-8-one-2-carboxylic acid. USE:Antibiotic. PREPARATION:An optically active isomer of formula (V-1) is acylated with a reactive derivative of a compound of formula II (Y is H, amine-protecting group) to give a compound of formula VIII. Then, the protecting groups are removed from the compound of formula VIII and, when necessary, the product is esterified to give the compound of formula I.</p> |
