Facile Access to Bicyclic Sultams with Methyl 1‐Sulfonylcyclopropane‐1‐carboxylate Moieties.

N-(2,3-Dibromopropyl)- and N-(3,4-dibromobutyl)(methoxycarbonyl)methanesulfanilides upon treatment with potassium carbonate in DMF furnish methyl 3-aryl-2,2-dioxo-2-thia-3-azabicyclo[n.1.0]alkane-1-carboxylates in yields ranging from 54 to 84 % (10 examples). The starting materials were obtained by sulfonylation of N-alkenylanilines with methyl (chlorosulfonyl)acetate and subsequent bromination. For the N-alkenylanilines (10 examples, 60–77 % yield) an efficient new synthesis employing a 2-nitrophenylsulfonyl substituent as a protective as well as an activating group has been developed. The 4-methoxyphenyl (PMP) group could easily be removed from the sultam nitrogen atom by treatment with cerium(IV) ammonium nitrate.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)