| abstract |
ABSTRACT OF THE DISCLOSURE New heterocyclic acetic acid compounds of the general formula (I), ( I) wherein y1 and y2 form together a removable carbonyl protecting group, and R is a removable amido protecting group, are prepared in the way that a compound of the general formula (III), ( III) wherein R, y1 and Y2 are as defined above, is activated on the carboxy group and then reacted with diazomethane, and the resulting compound of the general formula (II), ( II) wherein R, y1 and y2 are as defined above, is subjected to diazoketone rearrangement in the presence of water. The new compounds according to the invention are valuable intermediates in the synthesis of thiena-mycin and thienamycin analogues. |