The Chemistry of the 6b-Thioamidopenam 1b-Sulfoxides. The 1,2,4-Dithiazineacetidinones and Thiazolineazetidinones

6β-Thioamidopenam 1β-sulfoxides on thermolysis gave methyl 2-(3-substituted 4,5-dithia-2,7-diazabicyclo[4.2.0]oct-2-en-8-one-7-yl)-3-methyl-but-3-enoate (1,2,4-dithiazineazetidinones). The reaction of these compounds with halogenating agents is discussed