Oxoamide-thioester condensation

In general, virtually any process leading to 4-azetidinylthioesters from penams was put to its best use by the oxoamide-thioester coupling. Preparation of FCE-22101, FCE 22891 and related penems, could be achieved in fewer steps [81,82,92,96,153]. In particular, the silver-assisted 1,2-cleavage of penicillins is ideally suited to accompany the phosphite-mediated condensation a unique... 

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