From Benzothiazolyldithioazetidinone Type C

From Benzothiazolyldithioazetidinone Type C). The disulphides (6), which are obtained by the reaction of penicillin sulphoxides and 2-mercaptobenzothiazole, give different products with bases, dependent on the structure of the substituents on the -lactam nitrogen e.g., [6 R = CH(C02H)C(Me)=CH2] gives (7) whilst [6 R = C(=CH2)C02CH2CCl3] gives (8).  

Antonova and D. Simov, Khim. Geterotsikl. Soedin., 1979, 1587 (Chem. Abstr., 1980, 92 110 883). 

Takahashi, N. Nimura, and H. Ogura, Chem. Pharm. Bull., 1979, 27, 1147. 

From y-Aminoalkyl Thioethers Type C). Oxidation of methionine with iodine gives S-methylisothiazolidinium-3-carboxylate (9). This is a general reaction for compounds having an amino-group that is y to a thioether function, and thus forms a convenient route for the preparation of N-protonated cyclic sulphilimines.  

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