Reactions of 1,2-thiazetidine 1,1-dioxides with organometallics:: β-elimination and N-S bond cleavage

Reactions of 4-nonsubstituted beta-sultams 1 with methyllithium gave only (E)-vinylsulfonamides 2, whereas 2-aminoethyl sulfones 3 were obtained as minor products by use of methylmagnesium bromide. Reactions of 4-monosubstituted beta-sultams 6 with organolithiums gave (E)-vinylsulfonamides 7 stereoselectively regardless of the configuration of 3- and 4-substituents. Treatment of 4,4-dimethyl-beta-sultam 8a with methylmagnesium bromide and methyllithium provided 2-aminoethyl sulfone 9 and bis-sulfone 10, respectively, and isopropyl phenyl sulfone 11 was obtained by use of phenyllithium or phenylmagnesium bromide. (C) 1998 Elsevier Science Ltd. All rights reserved.