The reaction of calcium naphthyridine‐2,7‐dicarboxylate (Cadcnp) with Ru2(OAc)4Cl in water resulted in the formation of Ca[Ru2(dcnp)(OAc)3]2 (3). X‐ray crystal structural analysis of 3 confirmed its molecular structure and showed that the calcium ion binds to the lateral carboxylate groups of four neighboring anionic units of [Ru2(dcnp)(μ‐OAc)3] and two acetone molecules to form a two‐dimensional framework. The RuII–RuII valence state of the diruthenium core was supported by superconducting quantum interference device (SQUID) magnetometry [μeff (300 K) = 2.77 μB]. Complex 3 appears to be an efficient catalyst for the oxidative cleavage of olefins in aqueous media under mild conditions. Typically, the reaction of pulegone with NaIO4 in water catalyzed by 3 (1 mol‐%) at 45 °C afforded 3‐methyladipic acid quantitatively.