synthesized by ring closing metathesis (RCM) of sulfonates. The resulting α,β-unsaturated sultones act as dienophiles in intermolecular Diels-Alder reactions. A first cyclic sulfate formation throughRCM has been discovered, and a rapid access to p-lactams fused to a sultam moiety of variable ring size was developed from inexpensive, commercially available starting materials using RCM as the key operation