Efficient asymmetric synthesis of 3-substituted β-sultams

The asymmetric synthesis of 3-substituted 1,2-thiazetidine 1,1-dioxides by cyclization of β-amino-sulfonyl chlorides is reported. The synthesis is based on the aza-Michael addition of (R,R,R)-2-amino-3-methoxymethyl-2-azabicyclo[3.3.0]octane (RAMBO) to alkenyl–sulfonates.