Synthesis of 1,2,5-Thiadiazolidines 1,1-dioxides (Cyclosulfamides) Starting from Amino Acids and Chlorosulfonyl Isocyanate

We report here a practical access to a series of five-membered cyclosulfamides (1,2,5-thiadiazolidines 1,1-dioxides) N2 substituted by the BOC group. These compounds are synthesized starting from chlorosulfonyl isocyanate and nitrogen mustards or amino acids. The derivatization of amino acids can lead to an alkyl group on C-4 with a well-defined configuration; in this case the N5 position was protected by a benzyl group. These compounds are valuable tools for asymmetric synthesis.