| 摘要 |
There is presented cephalosporin derivatives which are the readily hydrolysable esters and ethers of compounds of the general formula <IMAGE> (I) wherein R represents furyl, thienyl or phenyl optionally substituted by halogen, hydroxy, lower alkoxy or lower alkyl, R1 represents lower alkyl or aminocarbonylmethyl and X represents a group of the formula <IMAGE> <IMAGE> <IMAGE> in which one of the two symbols R2 and R3 represents hydrogen and the other represents lower alkyl and R4 represents lower alkyl, as well as salts of said esters and ethers and hydrates of said esters, ethers and salts. |
