| 摘要 |
NEW MATERIAL:A compound shown by the formula I (R<1> is alkyl, aryl, or aralkyl; R<3> is H, or ester residue; R<4> is akyl, aryl, or aralkyl). EXAMPLE:5-Methylseleno-6-methoxypenam-3-carboxylic acid methyl ester. USE:An intermediate for producing 6-oxypenam useful as beta-lactamase inhibitor, etc. PREPARATION:A reactive derivative of a carboxylic acid shown by the formula R<1>O-CH2COOH is reacted with a compound (e.g., 2-methylseleno-4-methoxy carbonyl-1,3-thiazoline, etc.) shown by the formula II (R<3> is ester residue) in the presence of a base such as triethylamine. |
