Stereoselective synthesis of β-sultams using chiral tricarbonyl(η6-arene)chromium(0) complexes

The reaction of (-)-1R- or (+)-1S-tricarbonyl(2-substituted benzaldehyde)chromium complexes with tert.-Bu methanesulfonamide dianion afforded, after decomplexation and intramol. cyclization, the enantiomerically pure N-tert-butyl-3-aryl-1,2-thiazetidine 1,1-dioxide derivs. The hydrolytic ring opening gave the corresponding enantiopure 1-aminosulfonic acid.