Abstract Methanobactin OB3b (Mbn‐OB3b) is a unique natural product with stunning affinity for copper ions ( K a ≈Cu(I) 10 34 ). Here, we report the first total synthesis of Cu(I)‐bound methanobactin OB3b featuring as key transformations a cyclodehydration‐thioacylation sequence, to generate the conjugated heterocyclic systems, and a copper‐templated cyclization, to complete the caged structure of the very sensitive target compound.