Although copper‐nitrene has been extensively studied as a versatile active species in various transformations, asymmetric reactions involving copper‐nitrene have been limited to the aziridination of olefins. Herein, we report the novel copper‐nitrene‐catalyzed desymmetric oxaziridination reaction of cyclic diketones with alkyl azides and the subsequent rearrangement of the resulting highly active intermediate, which produces a synthetically challenging chiral bicyclic lactam containing a quaternary carbon center. This procedure not only enriches the copper‐nitrene‐catalyzed asymmetric reactions, but also provides an alternative strategy to address the inherent challenges of catalytic asymmetric Schmidt reactions. This unique reaction could inspire the investigation of novel copper‐nitrene‐catalyzed asymmetric transformations and their reaction mechanisms.