| 摘要 |
NEW MATERIAL:The compound of formula I {R<1> is H, lower alkyl, (substituted) benzyl, (substituted) phenyl, alkali metal or ammonium; R<2> is H or -SR<4> [R<4> is lower alkyl or (substituted) benzyl]; R<3> is lower alkyl, (substituted) benzyl or (substituted) phenyl}. EXAMPLE:DELTA<2>-1,3-Selenazoline-4-carboxylic acid methyl ester. USE:A nucleus of an antibiotic substance having broad anti-bacterial spectrum and its production intermediate. PREPARATION:A selenium-containing carboxylic acid derivative of formula II is made to react with a ketene derivative of formula R<3>O-CH=C=O. |
