Thermolysis of penicillin-derived sulphoxides in the presence of thioacids offers a simple route to 4-acyldithioazetidin-2-ones, whose desulphurisatio yields key intermediates for the synthesis of penem antibiotics.
Desulphurative approaches to penem antibiotics. II. 4-acyldithioazetidin-2-ones from penicillin derived sulphenimides, thiolsulphonates and disulphides.