| abstract |
A process for the preparation of compounds of formula (I) <IMAGE> (I) wherein R1 is hydrogen or an organic group; R2 is hydrogen or a carboxy protecting group; and Y is a group-S-heterocyclic, acyloxy, alkoxy, alkylthio, pyridyl, which group may be substituted, or azido, and penem derivatives falling within the scope of formula (I) and pharmaceutically or veterinarily acceptable salts thereof. The process involves displacing a group L in the Y position with a reagent Y-H. |